[29189] in North American Network Operators' Group
Re: UUnet blocking ICMP ECHO for select sources/destinations ?
daemon@ATHENA.MIT.EDU (Kai Schlichting)
Wed Jun 14 16:49:15 2000
Message-Id: <4.2.2.20000614164232.02f32bd0@mail.speedus.net>
Date: Wed, 14 Jun 2000 16:47:35 -0400
To: Mufti Ahmed <Mufti.Ahmed@reuters.com>
From: Kai Schlichting <kai@pac-rim.net>
Cc: nanog@merit.edu
In-Reply-To: <200006142017.QAA16676@conti.nu>
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The observations suggest something different. Remember that I mentioned
that this blockage only occurs for a SINGLE IP in my network: the base
IP belonging to the server doing the stats collection every 5 minutes. Other
IP's (even on that server) are ok. Rate limiting would be visible as packet
loss after the committed rate is exceeded: you can't rate-limit on production border routers down to single-host granularity, only a big interface-wide
rate-limit will work. I am still trying to determine if the interface IP
in question is the customer side of things, but things are a bit murky
there, because there appear to be ACLs on both sides of the link.
At Wednesday 04:15 PM 6/14/00 , Mufti Ahmed <Mufti.Ahmed@reuters.com> wrote:
> Kai what if UUnet is running some type of QOS mechanism in their
>core network that prevents massive amounts of icmp messages
>traveling through? Maybe they are rate-limiting everyone with CAR.
>Their infrastructure is interesting they use Cisco, Fore, and Juniper
>at least in production. And they claim they run an MPLS network;
>maybe this is where icmp traffic is killed..
