Mailing List Archive

DSCP Marking on BigIrons
Hi,

I'm having some real trouble working out how to dscp mark packets on an
incoming interface (either a vlan or a ve).

Looking at the qos functions there's only:

qos-tos mark dscp

The documentation has this to say on the subject:

qos mark cos

Syntax: [no] qos mark cos | dscp

The cos | dscp parameter specifies the type of marking.

* cos - The device changes the outbound packet's 802.1Q
priority value to match the results of the device's QoS mapping
from the ToS value (IP precedence or DSCP) into the 802.1Q value.

* dscp - The device changes the outbound packet's ToS value to
match the results of the device's QoS mapping from IP precedence
to DSCP.

Which seems to imply that the device will map the outbound packets based on the
IP precendence value. This isn't what I want to do here - I wish to mark
packets as they arrive on an interface to a specific DCSP value.

We don't actually wish to do any QoS based on the DSCP value. We want to mark
traffic from directly connected peers with a nominal DSCP value, which we use
in policy routing in some places in our network.

For example, for billing purposes, we would rewrite the next-hop for destined
for some customers and from a directly connected peer:

route-map POLICY_PARTIAL permit 10
match ip address ACL_S_DIRECT_PEER
match ip address prefix-list PFX_CUST_1
set ip next-hop x.y.z.w

ip access-list extended ACL_S_DIRECT_PEER
permit ip any any dscp-mapping 14
deny ip any any

On our cisco's we mark the traffic thus:

class-map match-any CM_ANY
match access-group name ACL_ANY
!
!
policy-map PM_MARK_DIRECT_PEER
class CM_ANY
set ip dscp 14

ip access-list extended ACL_ANY
permit ip any any

int vlan xxx
service-policy input PM_MARK_DIRECT_PEER

The Foundry's in our network are able to utilise this marking for policy
routing as shown above, but I'm unable to figure out how to do the marking.

Is this possible on the BigIrons? If not would the NetIrons be capable?

Sam