[j-nsp] compound rewrite-rule

Luca Tosolini bit.gossip at chello.nl
Mon Sep 6 12:37:54 EDT 2010


Experts,
on Mx and Junos 10.2R2.11
the following rewrite-rules configuration:
show configuration class-of-service interfaces xe-4/1/0  
unit 0 {
    classifiers {
        exp MPLS;
        ieee-802.1 DOT1P;
        inet-precedence TOS;
    }
    rewrite-rules {
        exp MPLS-RW;
        ieee-802.1 DOT1P-RW;
        inet-precedence TOS-RW;
    }
}

It looks like only one of the rewrite is executed but not all of them;
see the following capture of an egress frame:

sudo tcpdump -i eth1 -n -v -c1 mpls
tcpdump: WARNING: eth1: no IPv4 address assigned
tcpdump: listening on eth1, link-type EN10MB (Ethernet), capture size
65535 bytes
16:12:14.043480 MPLS (label 0 (IPv4 explicit NULL), exp 6, [S], ttl 62)
	IP (tos 0x0, ttl 63, id 0, offset 0, flags [none], proto UDP (17),
length 114)


Here exp=6 and tos=0 so for an MPLS packet only MPLS-RW is executed.
Instead on a IP frame I see that TOS-RW is executed.

So it looks that the rewrite-rules are NOT executed together on same
frame !!
Is this the wanted behavior?

Thanks,
Bit.



More information about the juniper-nsp mailing list