[j-nsp] JUNOS ping utility and fragmented ICMP "echo request" probes

[Martin T]

Steinar,
yes, I agree. Packets should be fragmented and they are fragmented.
However, why doesn't Cisco 891 send back fragmented ICMP "echo
replies"? Unfortunately I don't manage this Cisco 891 so I'm not able
to run debug on the Cisco 891. Or does JUNOS drop fragmented ICMP
"echo replies" by default to RE?


regards,
martin


2011/10/11  <sthaug at nethelp.no>:
>> Cisco891 has IPv4 address 10.10.10.2 and Juniper M10i has IPv4 address
>> 10.10.10.1. If I execute "ping 10.10.10.2 source 10.10.10.1 size 1473
>> count 1"(or larger packet size) in M10i and tcpdump traffic, I can see
>> following:
>
> Ping size 1500 on the Cisco side = ping size 1472 on the Juniper side.
>
> If you ping from the Juniper with size 1473, you should expect the
> packet to be fragmented.
>
> Steinar Haug, Nethelp consulting, sthaug at nethelp.no
>