[j-nsp] per-flow load balancing hash and ICMP traffic

[Mark Miklic]

Rafal,

indeed, your explanation is correct. I guess there is no bypassing it...

Thanks,
Mark

2006/12/8, Rafał Szarecki <rszarecki at gmail.com>:
>
> Mark,
>
> It is interesting what U describe. I rather expect that removing
> destination-port from hash will put all ICMP packet on same  link.
> If U configure 'source-port' actualy ASIC is look at first 2 Bytes after
> end of IP Header. This 2 B for ICMP are TYPE and CODE field. So they will
> should do not varry.
> The destination-port is matching 3rd and 4th Byte, where ICMP has
> checksum. and this value of course can varry. So use of this for hash, will
> result in load-ballancing.
>
> BTW as ASIC just takes some bytes form packet, they are protocol unaware.
> And if in FirewallFilter you configure some 'destination-port' without
> protocol (tcp/udp), it can results in matching of ICMP, raw IP or other
> packets which has no port at leyer 4.
>
> 2006/12/7, Mark Miklic <mmiklic at gmail.com>:
> >
> > Ok, problem solved (thanks Ray;).
> >
> > Seems like the source-port for layer-4 hash equals to datagram id for
> > ICMP.
> > Really interesting...
> >
> > Mark
> >
> > 2006/12/7, Mark Miklic < mmiklic at gmail.com>:
> > >
> > > Actually,
> > >
> > > it is enough if I exclude source-port from the hash. This is even more
> > > confusing... I thought mtr had nothing to do with layer-4 source ports
> > and
> > > such, being ICMP. Is perhaps the sequence number treated as the source
> > port?
> > > Any ideas?
> > >
> > > Thanks,
> > > Mark
> > >
> > >
> > > 2006/12/7, Mark Miklic < mmiklic at gmail.com>:
> > > >
> > > > Anyone knows how ICMP is being treated when layer-4 hash option (any
> > of
> > > > them) is being turned on?
> > > >
> > > > I was doing some tests today, and the only way I could ensure a
> > > > consistent path for MTR through the per-flow lb-ed network was to
> > exclude
> > > > layer-4 parameter hashing completely.
> > > >
> > > > The only thing that comes to my mind is that Juniper introduces
> > random
> > > > values if there is no layer-4 information in the datagram...Is there
> > any
> > > > option to bypass this, or perhaps I am barking at the wrong tree?
> > > >
> > > > Thanks,
> > > > Mark
> > > >
> > >
> > >
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> >
>
>
>
> --
> Rafał Szarecki JNCIE
> +48602418971