RFC 8900 says network operators MUST NOT filter ICMPv6 Packet Too Big messages unless they are known to be forged.
Checked 2026-10-02
- Vendor
- not restricted
- Product
- not restricted
- Subsystem
- Path MTU discovery
- Deployment
- on-premises, multi-tenant
- Region
- not restricted
- Release range
- BCP 230 as published
- Checked
- 2026-10-02
Sources
- RFC 8900: IP Fragmentation Considered Fragile — RFC Editor (IETF) · tier 1 standards and regulators · Section 6.5
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting failed calls caused by large SIP messages over UDP: source note sip-fragmentation-troubleshooting-rfc8900-no-filter-ptb. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-fragmentation-troubleshooting-rfc8900-no-filter-ptb
BibTeX
@misc{warmtransfer-claim-sip-fragmentation-troubleshooting-rfc8900-no-filter-ptb,
title = {Troubleshooting failed calls caused by large SIP messages over UDP: source note sip-fragmentation-troubleshooting-rfc8900-no-filter-ptb},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-fragmentation-troubleshooting-rfc8900-no-filter-ptb},
note = {Source note sip-fragmentation-troubleshooting-rfc8900-no-filter-ptb, checked 2026-10-02}
}