IPv6 MTU Path Discovery - Cisco

Jun 06, 2012 Discarded UDP datagram over MTU size with IPv6 - Stack Discarded UDP datagram over MTU size with IPv6. Ask Question Asked 6 years, 7 months ago. Active 6 years, 7 months ago. Viewed 266 times 0. I've found out that when I send an UDP datagram that gets fragmented (over 1452 bytes with MTU=1500), according to tcpdump, all the fragments are received on the target machine but then no message is [SOLVED] OpenWRT: IPv6 MTU problem, routing slow, packet loss Sep 12, 2010 IPv6 test - IPv6/4 connectivity and speed test Testing packet size: 1500 Result: no PMTUD problems detected no PMTUD problems detected

Hi, Curious problem with IPV6. Situation is wget request from squid proxy via intermediate router. With IPV4 (wget -4) speed is ~100MB/sec. With IPV6 (wget -6) it drops to 30KB/sec. Examining the traffic with tcpdump shows that the squid box is regularly sending out over-sized packets (>MTU) (5 Replies)

mtuと直接は関係ないことですが、最近ではpppoeセッションの通信負荷が問題となっておりipv6のipoe方式を利用できるプロバイダも増えてきています。 ipoe方式の場合、ipv6はmtuの上限値が1500バイトのまま利用することができます。 MTU issues (and TCP MSS clamping) in residential IPv6 Jan 28, 2013 Network MTU vs. Maximum TCP - Lifewire

Router(config-if)# ipv6 mtu 1400 This MSS option does not work for UDP applications because there is no way to negotiate this during the handshake because UDP is a connectionless protocol.

For link layers that can support a configurable MTU size, RFC 2460 recommends that they be configured with an MTU size of at least 1500 bytes (the IPv6 MTU for Ethernet II encapsulation). An example of a configurable MTU is the Maximum Receive Unit (MRU) of a Point-to-Point Protocol (PPP) link.