l***y
发帖数: 791 | 1 In the rfc it says mpls forwarding state means either in-lable/outlabel-
nexthop for non-ingress or fec/out-label-nexthop for ingress, but what is '
next hop' in this context? Interface or next hop neighbor ip?
So if IGP updates but for some reason nothing updates ldp, i.e. if ospf
routes around a router with dead RE because ospf timed out but nothing else
has gone down (ldp has much larger hold timer), would mpls forwarding still
happen towards this router with dead RE?
Also, i'm reading about the two distribution mode, downstream unsolicited
and what's-the-other-one. Does it make any difference? | s*****g
发帖数: 1055 | 2 The same problem exists between IGP and BGP, what was the solution for that?
It makes a difference but the most vendors implement ordered control with
downstream unsolicited. i.e, a LSR only advertises a label for a FEC (
usually /32 loopbacks by default but other FECs can be injected by
configuration) upstream when a FEC is egress or when it has a mapping for
that FEC. | z**r
发帖数: 17771 | 3 for your 1st question: cisco routers would rely on CEF table (adj table).
for your second question: come on, just read
ios>
else
still
【在 l***y 的大作中提到】
: In the rfc it says mpls forwarding state means either in-lable/outlabel-
: nexthop for non-ingress or fec/out-label-nexthop for ingress, but what is '
: next hop' in this context? Interface or next hop neighbor ip?
: So if IGP updates but for some reason nothing updates ldp, i.e. if ospf
: routes around a router with dead RE because ospf timed out but nothing else
: has gone down (ldp has much larger hold timer), would mpls forwarding still
: happen towards this router with dead RE?
: Also, i'm reading about the two distribution mode, downstream unsolicited
: and what's-the-other-one. Does it make any difference?
| l***y
发帖数: 791 | 4 found some info from rfc for my 2nd and 3rd question. for first question,
I'm hoping to find this out for Juniper. =(((
【在 z**r 的大作中提到】
: for your 1st question: cisco routers would rely on CEF table (adj table).
: for your second question: come on, just read : ios>
:
: else
: still
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