PMTUD broken with ipv6.juniper.net?

[Daniel Roesen]

On Wed, Feb 02, 2011 at 07:47:38AM -0500, Jared Mauch wrote:
> I want to get the broken network elements fixed.  If you see any in
> the NTT network, please let me know as I want to solve it.

Not really your network, but your customer.

It looks like PMTUD is broken on http://ipv6.juniper.net/ - folks with
MTU 1500 IPv6 access have no problems, but I'm behind a tunnel at home,
but not doing MSS clamping, so advertising MSS=1440. Net result looks
like "something" is prolly filtering the ICMP frag needed packets from
the tunnel broker.

Forward path: SixXS broker at AS8422 -> AS1299 -> NTT -> JNPR

...
 14   182 ms   182 ms   182 ms  ae-1.r06.mlpsca01.us.bb.gin.ntt.net [2001:418:0:2000::366]
 15   183 ms   182 ms   196 ms  fa-0.juniper-networks.mlpsca01.us.bb.gin.ntt.net [2001:418:9800:5000::6]
 16     *        *        *     Request timed out.

Source IP within 2001:4dd0:fea5::/48

If you have contacts for IPv6 firewalls at JNPR, would be nice to get in
touch with them sorting that out. Cannot be that they completely filter
ICMP for s3cUriTy? :-P


Best regards,
Daniel

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