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LTM routing question

TomNSCPO8_12229
Nimbostratus
Nimbostratus

front end self IP 192.168.80.9 back end self IP 192.168.180.9 (single LTM)

 

Quick Question on LTM. If I have a request come from 10.2.2.3 and it resolves to a virtual server 192.168.80.80 (Front end) and that VS selects (back end)pool member 192.168.180.82 in a pool I understand that the responding pool member uses its default gateway 192.168.180.1 but how does 192.168.180.9 know to send the request to 192.168.80.9 (front end self IP) for transmission back to 10.2.2.3 via 192.168.80.80? Since the Source address never changed (not using SNAT) is it just an entry on the F5 when it "proxies" the request that remains in the LTM?

 

Thanks please let me know if I need to clarify more. JUst trying to understand all steps in a request that has both subnets setup on the box.

 

2 REPLIES 2

Andy_McGrath
Cumulonimbus
Cumulonimbus

Your question is not very clear but as you have stated you are not used SNAT any return traffic needs to route via the F5 LTM.

 

Can be default route or specific route via the F5 Self IP if this is not the case then need to turn on SNAT or look at direct server response, used to be called nPath.

 

habib_Khan
Nimbostratus
Nimbostratus

Source:10.2.2.3 VIP:192.168.80.80 Pool: 192.168.180.82 Gateway: 192.168.180.1 || Ques: Self ip --192.168.180.9 Self ip 2 -- 192.168.80.9 || LTM is reverse proxy -- device or service placed between a client and a server in a network infrastructure. Incoming requests are handled by the LTM, which interacts on behalf of the client with the desired server or service residing on the server.

 

In your case LTM knows whats the next hope to reach 10.2.2.3 and as self ip reside within LTM- ARP place a role to make sure which interface/vlan has self ip configured.