From: Mark Lewis (mark@mjlnet.com)
Date: Thu Aug 03 2006 - 15:22:07 ART
Hi,
Routing protocols such as BGP are marked with IP Prec/CS 6 by originating routers.
Here's a list:
EGP/IGP/MCAST PROT: BGP, EIGRP, OSPF, RIP, PIM, MSDP, IGMP -- all marked with IP Prec/CS 6.
Other misc control protocols: LDP, RSVP-TE, L2TP control traffic, BFD-- all marked IP Prec/CS 6.
Management/diagnostics protocols: ICMP, NTP, Telnet-- all marked IP Prec/CS 6.
You'll notice that lack of protocols that marked CS7! There's a bit of confusion because IP Prec 6 is 'Internetwork Control' and IP Prec 7 is 'Network Control'. But Cisco routers don't mark any routing/control/management protocol traffic with IP Prec 7.
If you are creating a QoS policy/design for a network, then you also might like to do a bit of research on 'PAK_PRIORITY' (an internal flag that routers use to ensure that locally generated control traffic is prioritized).
HTH,
Mark
CCIE#6280 / CCSI#21051 / JNCIS#121 / etc.
Author:
www.ciscopress.com/title/1587051796
www.ciscopress.com/title/1587051044
>From: Carlos G Mendioroz <tron@huapi.ba.ar>
>Reply-To: Carlos G Mendioroz <tron@huapi.ba.ar>
>To: CCIEBOB <cciebob@comcast.net>
>CC: ccielab@groupstudy.com
>Subject: Re: TOS reserved bits 6/7 and routing protocols
>Date: Thu, 03 Aug 2006 13:45:21 -0400
>
>Might it be that that person confused IPP 6/7 whith ToS bits 6-7 ?
>It seems to be a common thing :)
>
>CCIEBOB @ 2/8/2006 10:59 -0400 dixit:
> > Hello all. I was recently told that some routing protocols (BGP) uses
>the reserved TOS bit for routing protocol establishment and updates. I
>could not find any documentation to support this. Does any one know if
>this statement is correct, and if so where can I find documentation on it?
>TIA. Bob
> >
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