pay.gov and IPv6

Carl Byington carl at five-ten-sg.com
Mon Nov 21 01:03:41 UTC 2016


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

On Mon, 2016-11-21 at 11:26 +1100, Mark Andrews wrote:
> And the advertised MSS was what?  On my box I'm seeing 1220 for
> IPv6 compared with 1460 for IPv4.  1220 shouldn't see PMTU problems.

  --> 2001:8d8:100f:f000::2d5 syn     w/ mss 1440
  <-- 2001:8d8:100f:f000::2d5 syn,ack w/ mss 1420
  --> 2001:8d8:100f:f000::2d5 ack
  --> 2001:8d8:100f:f000::2d5 GET / HTTP/1.1
  <-- 2001:8d8:100f:f000::2d5 ack
  <-- 2001:8d8:100f:f000::2d5 data...


data is a 1480 byte ipv6 packet:

ip6.header.payload.length = 1440 which is the tcp packet
tcp.header.length = 32 bytes
tcp.data.size = 1408 bytes (http response)


-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.14 (GNU/Linux)

iEYEAREKAAYFAlgyRUYACgkQL6j7milTFsH8tgCeLB9E9C2pjFqgp1w2YpipmvzZ
ib4Ani/cQmAgEo3QPfA9hMntGq4VLoO/
=mmCW
-----END PGP SIGNATURE-----





More information about the NANOG mailing list