[j-nsp] Limit on interfaces in bundle

Adam Vitkovsky Adam.Vitkovsky at gamma.co.uk
Thu Oct 29 19:35:46 EDT 2015

Hey Cydon,

> From: Cydon Satyr [mailto:cydonsatyr at gmail.com]
> Sent: Thursday, October 29, 2015 10:55 PM
> Hey all,
> Adam I believe that is correct. If I remember this, if it's something other than
> 0x4/0x6 Trio chip looks at bits after first 12 bytes; if it's 0x0800/0x86dd it still
> load balances this packet based on IPv4/IPv6 rules, and if it's 0x8100 it skips
> up to two vlan headers and again checks for real ethertype.  If it's something
> other than this it stops and just load balances used MPLS tags.
> So if there's CW, it still check for three things above (since CW doesn't start
> with 0x4/0x6), and then just fails. I think...
> How would router be certain of packet type based on packet length?
> Also since hashing is decided on ingress PFE if next-hop is aggregate/ecmp,
> trio only looks at first 128bytes or so. So probably looking at 0x4/0x6 is the
> cheapest/fastest way of guessing without performance penalty...
> Somebody correct me if I'm wrong
> BR
For labelled traffic it should be:
label 1-5 (by default)
MPLS Payload (L3-header for L3VPN packets or L2-header for L2VPN/PW packets)

And the LU chip should receive 320B chunk so there should be enough space to base the hash on 5Labels,CW,DMAC,SMAC,2VLANs,DIP,SIP,DPort,SPort but I don’t know if it’s implemented like this –it needs to be tested and documented.


        Adam Vitkovsky
        IP Engineer

T:      0333 006 5936
E:      Adam.Vitkovsky at gamma.co.uk
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