Federal Circuit Appeal No. 2024-2373

I'll research this case thoroughly, starting with the appeal docket and the underlying patent.

I found key results—this is a Federal Circuit Rule 36 affirmance from June 2026 involving Centripetal Networks. Let me dig deeper into the underlying litigation and IPRs.

Excellent progress. This is an IPR appeal, not a direct infringement appeal, with deep ties to the E.D. Va. jury trial. Let me verify the district court cases against both appellees, the company backgrounds, and the CAFC docket.

Case Overview: Centripetal Networks, LLC v. Keysight Technologies, Inc. & Palo Alto Networks, Inc., Fed. Cir. Nos. 2024-2372, 2024-2373

Parties and their roles. This is a patent-owner appeal by Centripetal Networks, LLC, a Virginia-based cybersecurity technology company (founded by Steven Rogers and Sean Moore, the named inventors on the patent at issue) that sells threat-intelligence-gateway appliances (CleanINTERNET/RuleGATE) but is best known as an aggressive patent enforcer against major network-security vendors — it obtained a ~$2.75 billion jury verdict against Cisco in 2020 that the Federal Circuit later reversed (Centripetal Networks, Inc. v. Cisco Sys., Inc., 2022 WL 2160571) over the trial judge's improper ex parte conduct. The appellees are Keysight Technologies, Inc., the California-based test-and-measurement/network-testing company that acquired Ixia in 2017, and Palo Alto Networks, Inc., the large-cap public firewall/cybersecurity vendor (NASDAQ: PANW). Both are accused infringers in Centripetal's E.D. Va. campaign; Keysight had earlier been sued by Centripetal over Ixia's ThreatARMOR and Vision ONE products (Centripetal Networks, Inc. v. Keysight Techs., Inc., No. 2:17-cv-00383 (E.D. Va.)) and ultimately settled — that settlement was later used as Centripetal's damages benchmark against Palo Alto.

The patent, accused technology, and procedural posture. The appeal concerns U.S. Patent No. 10,785,266 B2, "Methods and Systems for Protecting a Secured Network" (issued Sept. 22, 2020; application 16/728,766), whose claims recite a plurality of "packet security gateways" collectively forming the entire interface across a protected network's boundary, coordinated by a security-policy management server that automatically creates/alters packet-filtering rules from malicious-host-tracker threat intelligence and distributes them for application to all traffic crossing the boundary. Centripetal asserted the '266 patent (among a family including the '437, '903, '573, '797, '380 and '343 patents) against Palo Alto's next-generation firewalls in Centripetal Networks, LLC v. Palo Alto Networks, Inc., No. 2:21-cv-00137 (E.D. Va., Norfolk Div., filed Mar. 12, 2021), which produced a Jan. 31, 2024 jury verdict of $151.5 million for infringement (later reduced to $113.6 million in an Oct. 31, 2024 post-trial ruling by Judge Elizabeth W. Hanes). In parallel, Keysight petitioned for IPR on Jan. 6, 2023 (IPR2023-00445, instituted July 24, 2023), and Palo Alto filed IPR2023-01329 on Aug. 21, 2023 with identical grounds plus a motion to join the Keysight proceeding (granted Feb. 22, 2024) — a classic co-defendant joinder play to share PTAB risk and estoppel exposure. On July 22, 2024, both PTAB panels (APJs Turner, Moore, and Amundson, Turner authoring) issued Final Written Decisions holding all 27 claims of the '266 patent unpatentable as obvious over the Law, Wood, and Jungck prior-art references. Centripetal appealed both decisions to the Federal Circuit (appeals filed Sept. 27, 2024; argued by Daniel J. Richardson of Sullivan & Cromwell for Centripetal, Jonathan I.M. Detrixhe of Reed Smith for Keysight, and Andrew T. Radsch of Munger, Tolles & Olson for Palo Alto). A per curiam panel of Judges Lourie, Cunningham, and Stark entered a nonprecedential Rule 36 judgment AFFIRMING on June 9, 2026 (CAFC Dkt. 24-2372 RULE 36 judgment). Caveat: the case metadata above lists the matter as "pending," but the court's public docket shows it was decided by summary affirmance in June 2026; I could not confirm via PACER whether any petition for rehearing or certiorari followed.

Why the case is notable. The appeal matters because the PTAB's invalidation — now affirmed — strips the '266 patent's claims from Centripetal's parallel E.D. Va. infringement action against Palo Alto, directly threatening the surviving nine-figure verdict tied to that litigation. It is also emblematic of (1) the multi-front war Centripetal has waged against cybersecurity incumbents (Cisco, Keysight/Ixia, Palo Alto) using patents on automated, threat-intelligence-driven packet filtering — an area where courts and the PTAB have repeatedly probed § 101 eligibility and obviousness; (2) the strategic use of identical-ground IPR joinder by multiple accused infringers to consolidate validity challenges; and (3) the Federal Circuit's increasingly frequent summary affirmance of PTAB obviousness findings, leaving no precedential guidance. Because the affirmance is a Rule 36 disposition, the technical merits of the Board's claim construction (e.g., the "entire interface across a boundary" preamble limitation that Centripetal had argued distinguished Law's network access devices) were never addressed in a published opinion.

I have strong foundational sources (RPX chronology, Law360 docket, the CAFC Rule 36 judgment itself, PTAB filings). Now let me dig deeper into the district-court phases: judges/reassignments, claim construction, trial scope (which four patents), the post-trial judgment, and the cross-appeals.

I hit my search-step budget, so a few finer details (claim-construction order text, CAFC docket numbers for the district-court cross-appeals, and the precise disposition of the '380 patent before trial) remain unverified. Everything below that is sourced is anchored to the cited search results; anything inferred is flagged as such.

Key Legal Developments & Outcome — Centripetal v. Palo Alto Networks ('266 patent family campaign)

A. Scope note / which "litigation" this covers

The metadata centers on CAFC Nos. 2024-2373 (and its companion 2024-2372) — Centripetal's appeals from the PTAB's IPR2023-01329 (Palo Alto Networks) and IPR2023-00445 (Keysight Technologies) final written decisions holding all 27 claims of U.S. Patent 10,785,266 unpatentable. The "infringement litigation" whose fate those IPRs affected is Centripetal Networks, LLC v. Palo Alto Networks, Inc., No. 2:21-cv-00137 (E.D. Va., Norfolk Div.). That district case asserted 13 Centripetal patents (including the '266), went to jury trial in Jan. 2024 on four of them, produced a $151.5M verdict later reduced to ~$113.6M, and was cross-appealed by both sides. The chronology below tracks that case, with the PTAB proceedings interleaved because they drove the case's shape.

B. Chronology of key developments

1. Filing & initial pleadings (2021)

• 2021-03-12 — Centripetal Networks, Inc. filed its complaint (ECF 1) in the Alexandria Division, E.D. Va., accusing PAN's next-generation firewalls (and Panorama, Cortex, AutoFocus, MineMeld, DNS Security products) of infringement; the case was immediately transferred to Norfolk (2021-03-15) before Judge Arenda L. Wright Allen and Magistrate Judge Robert J. Krask. RPX's case summary identifies the original pleading as asserting infringement of a dozen-plus patents and seeking monetary damages, treble damages for willfulness, and a permanent injunction (Justia docket order, ECF 285).
• 2021-04-30 — PAN moved to dismiss under Rule 12(b)(6) (ECF 42/43): § 101 ineligibility of the '126, '028, and '246 patents as directed to abstract "rule-based packet filtering," plus pleading-deficiency attacks on pre-suit knowledge/willfulness, contributory infringement, and direct/indirect infringement specificity.
• 2021-06-09 — Case reassigned from Judge Wright Allen to Judge Roderick C. Young.
• 2021-07-09 — Centripetal filed its Amended Complaint, adding a newly issued thirteenth patent (U.S. 10,931,797); the '266 patent (issued 2020-09-22) was among the 13 asserted. The initial MTD was terminated as moot.
• 2021-07-30 — PAN renewed its motion to dismiss against the Amended Complaint (ECF 96), realleging Alice ineligibility and the same pleading deficiencies.
• 2021-08-02 — PAN filed its Answer to the Amended Complaint (per docket; counterclaim contents not verified in my sources).
• 2021-07/08 — PAN opened its PTAB front: 13 IPR petitions + 1 PGR (July–August 2021) challenging all claims of all 13 asserted patents (Notice, ECF 100, filed 2021-08-04).

2. Key pre-trial motions: stay, disqualification, dismissal (2021–2022)

• 2021-07-09 — PAN moved to stay the district case pending the PTAB proceedings.
• 2021-07-21 — Centripetal moved to disqualify PAN's counsel Ropes & Gray (ECF 73), alleging an implied attorney-client relationship from Ropes & Gray's representation of Silver Point Finance in a Dec. 2020 financing negotiation with Centripetal (the NDA was signed 2020-12-24). The PTAB separately rejected a similar disqualification motion in PAN's IPRs.
• 2022-02-23 — Status notice (ECF 274): of PAN's 13 IPRs + PGR, the PTAB had instituted five IPRs, denied six IPRs and the PGR, with two unresolved.
• 2022-03-01/02 — Judge Young's consolidated opinion (ECF 285, 23 pp.): granted PAN's stay pending the PTAB proceedings (early-stage litigation, simplification potential, no undue prejudice); denied Centripetal's motion to disqualify Ropes & Gray (no attorney-client relationship; Centripetal misconstrued the NDA/common-interest framing); denied PAN's motion to dismiss without prejudice to renewal after the stay. (Centripetal Networks, Inc. v. Palo Alto Networks, Inc., ECF 285; RPX case note; Justia/Casetext copies.)
• 2022-08-23 — Case reassigned to Judge Elizabeth W. Hanes (with Magistrate Judge Lawrence R. Leonard later on the docket). Reassignment reason not verified (aggregator docket data only).

3. PTAB phase one — and its litigation effect (2022–2023)

• 2022–2023 — PTAB final written decisions in PAN's instituted IPRs invalidated six asserted patents: the '028, '126, '413, '246, '906, and '899 (RPX; status chart at ECF 329-8, 2023-03-29). Centripetal's '903-family claims survived: the Board held asserted claims of the '903 patent not unpatentable, and the '437/'266 IPR petitions had been denied institution.
• 2023-05 — Following those FWDs, Judge Hanes lifted the stay on the surviving patent claims.
• 2023-07-24 — New third-party pressure: PTAB instituted Keysight's IPR2023-00445 on the '266 patent (petition filed 2023-01-06). Keysight also petitioned IPR2023-00448 against the related '474 patent. (The Keysight institution-Due-Date table appears at ECF 329-8.)
• 2023-08 — With the PTAB instituting review on the '266 (Keysight's) and '343 patents, the parties jointly moved to stay the claims based on those patents, and the court granted the stay — so the '266-based claims were stayed during trial and the jury never reached them. RPX describes the remaining active patents after this second stay as the '437, '380, '573, '903, and '797.
• 2023-08-21 — PAN filed IPR2023-01329 on the '266 patent with grounds identical to Keysight's IPR2023-00445, plus a concurrent motion for joinder (the petition expressly identifies the parallel E.D. Va. case and the Keysight E.D. Va. case, No. 2:22-cv-00002). This is the classic co-defendant "me-too + joinder" play to share PTAB risk/estoppel.
• 2024-02-22 — PTAB granted institution and joinder in IPR2023-01329 (Patexia docket: institution decision date 2024-02-22), making PAN a joined petitioner in the '266 review alongside Keysight.

4. Claim construction & remaining pre-trial skirmishes (2023–early 2024)

• I could not retrieve the district court's Markman order or its date from my searches; E.D. Va. practice there produced no readily public claim-construction opinion in the sources found. Note that the '266 claims were stayed in the district case, so the operative '266 constructions were the PTAB's in the IPR (which Centripetal contested on appeal, chiefly over whether the "entire interface across a boundary" preamble language distinguished the Law reference).
• 2024-01-03 — Judge Hanes denied PAN's bid to "trim" claims before trial (Law360, 2024-01-03: PAN "failed to persuade" the court to cut anything from the case before the jury).
• 2024-01-19 — Judge Hanes denied Centripetal's motion for partial summary judgment, finding a genuine dispute of material fact on validity of a disputed claim (Law360, 2024-01-19).

5. Trial, verdict, and post-trial motions (Jan.–Oct. 2024)

• 2024-01-16 to 2024-01-31 — Jury trial before Judge Hanes in Norfolk on four patents (identified in the trial/post-trial record as the '437 patent and the three "Correlation Patents" '903/'573/'797; Kramer Levin's firm announcement likewise says the jury found infringement of "all four of the Centripetal patents at issue"). Trial minute entries (Law360 docket) show trial days running through 2024-01-29 (Day #6), on which the court granted PAN's Rule 50(a) motion as to infringement of the '903, '573, and '797 patents under the doctrine of equivalents, taking remaining issues under advisement.
• 2024-01-31 — Jury verdict for Centripetal: PAN's NGFW products infringed all four tried patents; $151.5 million in lump-sum damages (Kramer Levin; Law360; some secondary sources round to $151.1M); the jury declined to find willfulness; it also found PAN failed to prove the claimed elements were well-understood, routine, and conventional (relevant to the § 101 defense submitted to the jury).
• 2024-02-29 — PAN filed post-trial motions: JMOL (ECF 900) and new trial (ECF 906), arguing the Correlation Patents are directed to ineligible abstract ideas, that improper evidence "infected the entire trial," and challenging damages. Centripetal opposed, urging the evidence supported liability and the award.
• 2024-07-22 — PTAB Final Written Decisions in IPR2023-00445 and IPR2023-01329: all 27 claims of the '266 patent unpatentable as obvious over the Law, Wood, and Jungck references (APJs Turner, Moore, Amundson; decision date per Patexia and the PTAB dockets). This is the decision Centripetal appealed in Nos. 2024-2372/2024-2373.
• Late Oct. 2024 — Judge Hanes's post-trial ruling (order; sealed memorandum opinion at ECF 970; Law360 reported 2024-10-31; public memorandum opinion later docketed, ECF 989): JMOL granted in part — no legally sufficient evidence of infringement of the '437 patent, and the damages award was reduced to $113.6M (Law360 headline figure; note one secondary source, Mondaq, states $116.3M — the difference appears to be interest/component accounting and I could not reconcile it from primary filings); new-trial motion denied; the jury verdict was otherwise sustained, including on § 101 for the Correlation Patents; Centripetal's own JMOL motion (ECF 841) and other pending motions (ECF 818, 847) were denied. Verdict form (ECF 851) noted in the opinion. The parties were directed to justify sealing by 2024-10-17, with the court signaling it would unseal most of the opinion.
• 2024-11 — Both parties appealed the district-court judgment to the Federal Circuit (per Mondaq's year-end damages roundup: "The parties both appealed in November"). I could not confirm the CAFC docket numbers or current status of those cross-appeals from my searches — flagging this as unverified.

6. Appeal of the IPR decisions and final disposition (2024–2026)

• 2024-09-27 — Centripetal appealed both PTAB FWDs to the Federal Circuit: No. 2024-2372 (from IPR2023-00445, Keysight) and No. 2024-2373 (from IPR2023-01329, PAN). Counsel per the Rule 36 judgment: Daniel J. Richardson (Sullivan & Cromwell) for Centripetal; Jonathan I.M. Detrixhe (Reed Smith) for Keysight; Andrew T. Radsch (Munger, Tolles & Olson) for Palo Alto.
• 2026-06-09 — Federal Circuit entered a nonprecedential Rule 36 judgment AFFIRMING the PTAB in both appeals: per curiam panel of Judges Lourie, Cunningham, and Stark, "AFFIRMED. See Fed. Cir. R. 36" (CAFC opinion/order PDF, 24-2372.RULE_36_JUDGMENT, 2026-06-09). Because it is a summary affirmance, the Board's claim construction (including the "entire interface across a boundary" preamble issue) was never addressed in a published opinion.
• Post-affirmance posture — I found no PACER-confirmed evidence of a petition for rehearing en banc or certiorari. The case metadata in your instructions says "pending," but the public CAFC docket shows the appeal was decided on 2026-06-09 — a contradiction to flag. The practical outcome: the '266 patent's claims are finally invalidated (subject to any further review), which extinguishes the stayed '266-based claims in the E.D. Va. action. The separate district-court judgment (reduced verdict on the '437/'903/'573/'797 patents) is the subject of the parties' pending cross-appeals, whose status I could not verify. Palo Alto's public filings as of 2025-04-30 still accrued $144.1M against the judgment plus estimated interest, with a $40.3M release during the nine months ended 2025-04-30 after the district court's reduction — indicating the money judgment remained live (and unpaid) through at least spring 2025.

C. Parallel PTAB proceedings on the asserted patents (effect on the litigation)

• PAN's 2021 IPR/PGR wave (13 IPRs + 1 PGR) — Institution on only five; FWDs invalidated the '028, '126, '413, '246, '906, and '899 patents, which is what shrank a 13-patent case to the handful that went to trial; Centripetal's appeals of several of those FWDs were active as of 2023–2025 (e.g., the CAFC's 2025-10-22 decision in related No. 2023-2027, involving a different Centripetal patent ('856), shows this family's IPR appeals remained contentious).
• '903 patent (Correlation family) — PTAB held asserted claims not unpatentable; that patent survived to trial and the jury's verdict.
• '266 patent — Institution of PAN's original petition was denied; validity pressure then came from Keysight IPR2023-00445 (filed 2023-01-06; instituted 2023-07-24) with PAN joining via IPR2023-01329 (filed 2023-08-21; institution + joinder 2024-02-22). The FWDs (2024-07-22) invalidated all 27 claims, and the CAFC affirmed (2026-06-09). Litigation effect: the '266 claims were stayed out of the Jan. 2024 trial, so the $151.5M→$113.6M verdict rested on other patents; the now-affirmed invalidation forecloses any later assertion of the '266 patent against PAN (and, via the IPR estoppel/joinder structure, binds both PAN and Keysight on the same grounds).
• Keysight context — Centripetal had separately sued Keysight (over Ixia's ThreatARMOR/Vision ONE) in No. 2:17-cv-00383 (E.D. Va.), which settled; that settlement was used as Centripetal's damages benchmark against Palo Alto. Keysight's '266 IPR (and its IPR on the child '474 patent) was the vehicle PAN joined — a coordinated co-defendant validity play.

D. Bottom-line outcome

• PTAB/CAFC (the appealed matter): The '266 patent is invalid — all 27 claims obvious over Law/Wood/Jungck — affirmed by summary Rule 36 judgment on 2026-06-09 (CAFC Nos. 2024-2372, 2024-2373). No precedential opinion; no confirmed further review.
• District court (the infringement case): Centripetal won a 2024-01-31 jury verdict of $151.5M (lump sum, no willfulness) on four patents; the court trimmed it to $113.6M in late Oct. 2024 by granting JMOL of non-infringement on the '437 patent; both sides appealed in Nov. 2024 — those cross-appeals were pending as of my last verified sources, and I could not confirm their disposition.
• Strategic significance: This is the second time Centripetal's flagship enforcement campaign has been substantially rolled back after a headline jury win (cf. the Federal Circuit's reversal of the ~$2.75B Cisco verdict), here through PTAB obviousness findings that the Federal Circuit summarily affirmed — leaving the surviving district-court judgment (on the non-'266 patents) as the only live component of the Palo Alto dispute.

Sources: CAFC Rule 36 judgment PDF (cafc.uscourts.gov, 2026-06-09); PACER-derived dockets via Justia/Casetext (ECF 285 opinion), Docket Alarm (ECF 96, 329-8), UniCourt, and Ex Parte (case status/docket periods); RPX litigation note on the case; Law360 docket pages and articles (2024-01-03, 2024-01-19, 2024-01-31, 2024-02-29, 2024-10-31); Kramer Levin announcements (Feb. 2024; Managing IP 2025 award); Patexia PTAB summary for IPR2023-01329; Palo Alto Networks SEC filings (10-Q/10-K, 2025); Mondaq 2024 damages roundup; Alston & Bird CAFC weekly summaries (Oct. 2025). Unverified items (cross-appeal docket numbers/status, Markman order, '380 patent's pre-trial disposition, any rehearing/cert petitions) are expressly flagged above.

Scope note: who is the "plaintiff" here

The case you're tracking (Fed. Cir. No. 2024-2373, consolidated with No. 2024-2372, Centripetal Networks, LLC v. Keysight Technologies, Inc. & Palo Alto Networks, Inc.) is a patent-owner appeal of IPR2023-01329/IPR2023-00445, not the infringement suit itself. There is no "plaintiff" caption on the Federal Circuit docket — Centripetal is the appellant and was the plaintiff in the underlying infringement case, Centripetal Networks, LLC (f/k/a Centripetal Networks, Inc.) v. Palo Alto Networks, Inc., No. 2:21-cv-00137 (E.D. Va., Norfolk Div.), in which the '266 patent was asserted and which produced the Jan. 31, 2024 $151.5M jury verdict. Counsel of record are below, organized by (A) the district-court infringement case and (B) the present Federal Circuit appeal. All names come from public docket filings and opinions; nothing is sealed that would obscure these appearances.

A. Plaintiff's counsel of record in the E.D. Va. infringement case (2:21-cv-00137)

The operative signature blocks (complaint-period filings, e.g., ECF No. 7 (3/12/2021); post-trial joint notice, ECF No. 860 (2/7/2024)) show a two-firm structure: Virginia local counsel + Kramer Levin Naftalis & Frankel LLP as national trial counsel.

Firm note: Kramer Levin Naftalis & Frankel LLP combined with Herbert Smith Freehills during 2025–2026 and now markets as Herbert Smith Freehills Kramer (its post-merger announcements of the Centripetal verdict appear on hsfkramer.com); at all times relevant to the litigation the attorneys appeared as Kramer Levin.

B. Counsel representing Centripetal (plaintiff/appellant) in the present Federal Circuit appeal, Nos. 2024-2372/2024-2373

Per the court's June 9, 2026 Rule 36 judgment in this appeal (CAFC Dkt. 24-2372, RULE 36 JUDGMENT, 6/9/2026), Centripetal was represented by Sullivan & Cromwell LLP:

For completeness on the appellee side (not asked, but relevant to the caption): Keysight was represented by Jonathan I.M. Detrixhe (Reed Smith, San Francisco — argued for all appellees), with Gerard M. Donovan (Reed Smith, Washington, DC) and Jonah D. Mitchell (Reed Smith, San Francisco); Palo Alto by Andrew T. Radsch (Munger, Tolles & Olson, San Francisco — formerly Ropes & Gray, Palo Alto).

C. Related representation you should not conflate

Centripetal's counsel varied by matter within this multi-front war, which can confuse "counsel of record" searches:

• PTAB-level counsel in the IPRs on the '266 patent (IPR2023-00445/01329) are not confirmed in my sources; by 2024 Centripetal had switched its appellate IPR briefing to Sullivan & Cromwell for this appeal, while in the other IPR appeals (Nos. 23-2027, 23-1636, etc.) it used Clement & Murphy PLLC (Paul D. Clement argued No. 23-2027; Matthew D. Rowen, Joseph J. DeMott, Mariel A. Brookins) with Dowd Scheffel PLLC (Matthew J. Dowd, Robert J. Scheffel). The appeal of the district-court judgment itself is Fed. Cir. No. 25-1167 (filed 11/13/2024 from 2:21-cv-00137), where Unicourt's docket listing shows Centripetal again represented by the Clement & Murphy/Dowd Scheffel group (Rowen, Eiswald, DeMott, Clement), not S&C.
• No in-house counsel for Centripetal Networks, LLC appears as counsel of record in any of the public dockets reviewed; the company appears to rely entirely on outside counsel in this litigation.
• Keysight's own earlier infringement case (Centripetal v. Keysight/Ixia, No. 2:17-cv-00383) was settled and is not the "plaintiff-side" case relevant to this appeal.

Bottom line: If "this patent infringement case" means the E.D. Va. action underlying the IPR appeals, plaintiff Centripetal's counsel of record are Stephen E. Noona (Kaufman & Canoles, Norfolk — lead/local) and the Kramer Levin trial team of Paul J. Andre, Lisa Kobialka, James R. Hannah, Hannah Y. Lee, Kris Kastens, Michael Lee, and Christina M. Finn (Redwood Shores/Menlo Park, pro hac vice). If it means the pending Federal Circuit appeal docketed as 2024-2373, then Centripetal's counsel of record are Daniel J. Richardson (argued), Aviv S. Halpern, and Andrei Iancu of Sullivan & Cromwell. I would flag that the Kramer Levin → HSF Kramer merger branding and the multiple appellate teams are the two most common sources of error in compiling this list.

Scope note

The case metadata identifies "this case" as Federal Circuit Appeal No. 2024-2373 (consolidated with No. 2024-2372) — Centripetal's appeal of the PTAB's IPR final written decisions invalidating U.S. Patent 10,785,266 (IPR2023-00445 filed by Keysight; IPR2023-01329 filed by Palo Alto Networks and joined). In that posture the "defendants" of the underlying E.D. Va. infringement campaign are the appellees, Palo Alto Networks, Inc. and Keysight Technologies, Inc. I therefore report (A) the district-court defense counsel who represented Palo Alto in the underlying infringement case (Centripetal Networks, LLC v. Palo Alto Networks, Inc., No. 2:21-cv-00137, E.D. Va.), which is the case that gave this IPR/appeal its practical significance, and (B) the counsel who defended Keysight in its E.D. Va. actions and who appeared for both appellees in the CAFC appeal. No in-house litigation counsel for either company appears on the public district-court or CAFC filings I could verify; all on-record appearances were outside counsel.

---

A. Palo Alto Networks — defendant in E.D. Va. No. 2:21-cv-00137

Source: the parties' Feb. 7, 2024 joint trial-transcript notice signature block (E.D. Va. 2:21-cv-00137, DocketAlarm doc. 860), the 2021 UniCourt attorney listing for the case, and the 7/21/2021 initial-pretrial-conference minute entry.

Virginia local counsel (McGuireWoods LLP)

• Robert McFarland — McGuireWoods LLP, Norfolk, VA (101 W. Main St., Ste. 9000); Virginia-bar counsel who appeared for PAN at hearings and signed trial filings. One-line note: veteran E.D. Va. trial lawyer; McGuireWoods' Norfolk IP/defense lead in this case.
• David E. Finkelson — McGuireWoods LLP, Richmond, VA (2812 Emerywood Pkwy., Ste. 220); also appeared at the initial pretrial conference. Note: McGuireWoods IP litigator; E.D. Va. local counsel for PAN throughout the case.

National trial counsel (pro hac vice)

• Brett C. Govett — Norton Rose Fulbright US LLP, Dallas, TX. Appeared for PAN from the outset (listed as a defendant attorney in 2021; appeared at the July 2021 initial pretrial conference). Note: NRF IP trial partner with a substantial track record in E.D. Va. and PTAB patent defense; widely regarded as PAN's lead trial lawyer in this action.
• Jacqueline G. Baker — Norton Rose Fulbright US LLP, Dallas, TX. Note: NRF IP partner (patent litigation/PTAB) on the PAN trial team.
• Richard S. Zembek — Norton Rose Fulbright US LLP (pro hac vice). Note: NRF IP litigator; also handled PAN's PTAB validity work in the Centripetal campaign.
• Eric B. Hall — Norton Rose Fulbright US LLP (pro hac vice). Note: NRF IP partner; one of PAN's listed defendant attorneys from the 2021 docket onward.
• Daniel A. Prati — Norton Rose Fulbright US LLP (pro hac vice). Note: NRF trial-team member appearing at the January/February 2024 trial stage.
• Daniel S. Leventhal — Norton Rose Fulbright US LLP (pro hac vice; listed as a defendant attorney in 2021 UniCourt data). Note: NRF IP litigator on the PAN team.
• Stephanie N. DeBrow — Norton Rose Fulbright US LLP, Austin, TX (pro hac vice). Note: NRF IP litigator on the PAN team.
• Talbot Hansum — Norton Rose Fulbright US LLP, Austin, TX (pro hac vice). Note: NRF IP litigator on the PAN trial team.

Caveat: I could not verify from the public record which NRF office Zembek, Hall, Prati, and Leventhal were based in (the signature block is truncated); the Dallas (Govett/Baker) and Austin (DeBrow/Hansum) office designations come directly from the filing.

Co-counsel at the trial stage (Ropes & Gray LLP)

• Andrew Townsend Radsch — Ropes & Gray LLP, East Palo Alto, CA (pro hac vice) at the time of the district-court filings. Note: originally PAN's PTAB/trial counsel; Centripetal's motion to disqualify Ropes & Gray (based on the firm's prior work for Centripetal's financier Silver Point) was denied by Judge Young in March 2022 (RPX coverage), so Ropes & Gray stayed on through trial. Radsch has since moved to Munger, Tolles & Olson (San Francisco) and appeared there for PAN in the CAFC appeal (see below).
• James Richard Batchelder — Ropes & Gray LLP, East Palo Alto, CA (pro hac vice). Note: Ropes & Gray's IP-litigation leader; long-time PAN counsel in the Centripetal multi-patent wars, including the related '856-IPR appeal (Fed. Cir. No. 23-2027).
• Josef Byks Schenker — Ropes & Gray LLP, New York, NY (pro hac vice). Note: Ropes & Gray IP litigator on the trial team.

Caveat on "lead" designations: no filing I found labels a single "lead trial counsel." The minute entry and trial filings show McFarland (McGuireWoods) and Govett (NRF) as the principal courtroom spokespeople for PAN; Govett/Baker/NRF and McFarland/Finkelson/McGuireWoods appear to have split national trial and Virginia-local roles respectively.

---

B. Keysight Technologies — defendant in its E.D. Va. cases and co-appellee

Keysight's infringement exposure to the '266 patent family stems from the parallel E.D. Va. litigation (the 2017 case against Keysight/Ixia, No. 2:17-cv-00383, dismissed by stipulation Oct. 11, 2018, and the later multi-forum campaign including E.D. Va. No. 2:22-cv-00002, ITC Inv. No. 337-TA-1314, and eight IPRs).

District court (No. 2:17-cv-00383, 2017–2018)

• William R. Poynter — Kaleo Legal, Virginia Beach, VA; Keysight/Ixia's Virginia local counsel in the 2017 E.D. Va. case (signed the joint stipulation of dismissal; appeared at depositions as defense counsel). Note: local E.D. Va. IP defense practitioner.
• Christine M. Morgan, James A. Daire, John P. Bovich, Jonah D. Mitchell, Doyle B. Johnson, and a sixth Reed Smith attorney (name truncated in the filing) — all pro hac vice, Reed Smith LLP; defense counsel for Keysight and Ixia. Morgan and Mitchell remain active on the Keysight account today (see below).

Current/global Keysight defense (Reed Smith LLP)

The Reed Smith attorney bios and CAFC briefs identify the firm's ongoing Keysight defense team:

• Seth B. Herring — Reed Smith (trial/IP partner), who describes representing Keysight in the multi-forum Centripetal dispute (E.D. Va., ITC, UPC, Germany, PTAB).
• Jonah D. Mitchell — Reed Smith, San Francisco, CA; on the Keysight defense from the 2017 case through the CAFC IPR appeals.
• Gerard M. Donovan — Reed Smith, Washington, DC; argued/appeared for Keysight in multiple CAFC IPR appeals (e.g., Nos. 24-1406, 24-2246) and co-appeared in this appeal.
• Christine M. Morgan — Reed Smith; longtime Keysight counsel (ITC trial win; 8-for-8 PTAB institution record per her bio).
• Jonathan Iain Max Detrixhe — Reed Smith, San Francisco, CA; argued for all appellees in CAFC Nos. 2024-2372/2024-2373 (Rule 36 judgment, June 9, 2026).
• Others appearing on Keysight CAFC briefs in related appeals: Peter J. Chassman and Michael John Forbes (Reed Smith, Houston, TX), Sidharth Kapoor, and James Christopher Martin (Reed Smith, Pittsburgh, PA).

---

C. Counsel of record for the appellees in the CAFC appeal (Nos. 2024-2372/2024-2373) — i.e., the defendants below

Per the Federal Circuit's June 9, 2026 Rule 36 judgment (CAFC Dkt. 24-2372/24-2373; available on the court's opinions page):

• Jonathan Iain Max Detrixhe (Reed Smith LLP, San Francisco, CA) — argued for all appellees; also on brief for Keysight with Jonah D. Mitchell (San Francisco) and Gerard M. Donovan (Washington, DC).
• Andrew T. Radsch — Munger, Tolles & Olson LLP, San Francisco, CA, for appellee Palo Alto Networks, Inc. (Radsch moved from Ropes & Gray to Munger Tolles after the district-court trial; he had earlier been PAN's Ropes & Gray counsel in this same litigation and in the related '856 IPR appeal, Fed. Cir. No. 23-2027).
• In the related '856-patent appeal (No. 23-2027), PAN was also represented by Douglas Hallward-Driemeier (Ropes & Gray, Washington, DC) and James R. Batchelder (Ropes & Gray, East Palo Alto), and Keysight by Gerard M. Donovan and Jonah D. Mitchell — per the CAFC's Oct. 22, 2025 opinion and the parties' certificates of interest on file.

---

Key caveats

• In-house counsel: No Palo Alto Networks or Keysight in-house attorneys appear as counsel of record in the public district-court or CAFC filings I reviewed; I did not identify their names and will not speculate.
• Rule 36 affirmance vs. "pending" metadata: The case metadata marks the appeal "pending," but the CAFC's public docket shows a nonprecedential Rule 36 affirmance entered June 9, 2026 in Nos. 2024-2372/2024-2373. I found no public record of a rehearing petition or certiorari filing.
• Undisclosed party entries: Because the underlying E.D. Va. docket is partially sealed (extensive sealed motions practice, including the disqualification fight), some later substitutions of counsel (e.g., post-October 2024 post-trial motions and any appeal of the damages judgment) may not be reflected in the sources above. The district-court jury-verdict appeal and the IPR appeals are separate CAFC dockets; if you need counsel of record for Palo Alto's appeal of the $113.6 million post-trial judgment specifically, that would be a distinct CAFC docket (likely filed after the Oct. 31, 2024 ruling) and should be checked on PACER directly.