Attached is one of our remote sites schema.
R1,R2 are provider termination routers at loc B. Router A is similarly device at loc A.MPLS cloud is the connecting link.
Both R1,R2 are terminated locally at loc B on a Layer3(6500) switch.
Now before its discussed, it would be better for me to let all know that this scenario(but not in current form, was initial stages for ideas) was put up earlier here & had very good feedbacks from Guisseppe, Joseph et al.Situation is this being remote site, i wasnt really involved in implementing this & due to problems now, it has been put back to me for further checks.The objectives for this site were:
-achieve inbound & outbound loadbalancing on both links alongwith redundancy.
R1,R2 are enabled with glbp for outbound loadsharing.Inbound is not really in our control as provider is involved between.They say inbound loadbalancing and/or symmetric traffic cant really be achieved as bgp uses best path always.
So they had to start with existing setup to meet their site deadline.Location B routers have gre tunnel pointing to Loc A router.
Reports say there is no real loadsharing happening inbound, most of the time it uses the 2nd link which also is the glbp active one.Outbound is reportedly more again with glbp active(2nd link), but very small bouts can be seen on first link as well.Please help me with your views.
1.How can i ascertain if outbound using glbp is indeed loadsharing on both links,as i understand that since the L3 switch is the one giving out arp & is seen as one & new host arp request would only come to L3 ports hooked to internal network; R1,R2 would rarely get newer arp replies to change link path(Correct if this is wrong).Any commands or other things to check with?
2.How to see if inbound loadsharing is happening , any commands or other things?
3.Would the failover time be glbp hold timer in lan side & bgp hold time in wan side(3 mins)?
4.Lastly, any suggestions , configs et al to actually change this to achieve the desired requirements of inbound & outbound loadbalancing alongwith symmetric flow if possible.
Thanks in advance.