[c-nsp] Question about class-map, policy-map and TOS field?

[Curtis Doty]

Andy Saykao wrote:
> What I don't get is - how do we set an ip tos value of 15 using
> policy-map when that option doesn't exist (see below).
>  
> Router(config)#policy-map TOS-TAG-IX-POLICY
> Router(config-pmap)#class TOS-TAG-IX-CLASS
> Router(config-pmap-c)#set ip ?
>   dscp        Set IP DSCP (DiffServ CodePoint)
>   precedence  Set IP precedence
>
> How do I set it so the incoming packets are marked with a TOS of 15 with
> policy-map???
>  
>   


The 6 dscp bits are a superset of the 3 old precedence bits.

If you could setttle for only tos 14, then maybe set ip dscp 7. But
alas, you wouldn't be setting the minimize cost bit. Which is now used
for ECN.

http://tools.ietf.org/html/rfc3168#section-22

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