Forum Discussion
Sumanta_88744
Cirrus
CirrusCreating an active-active DSC configuration with OSPF routing on 11.x
Hi Experts
I have to do a deployment of active/active VIPRION 2400 chassis, running 2250 blades. As per below link, we need to create two traffic groups for each VLAN. How will the default routi...
Kevin_Davies_40
Nacreous
NacreousSumanta,
You should not have to advertise any routes for virtual servers. The router attached to that VLAN where the virtual's are listening should automatically advertise the attached network if its participating in OSPF. When the traffic arrives at the router then it will forward the incoming traffic to the virtual server. Which F5 it goes to will depend entirely on which BIGIP is currently hosting that virtual servers address. This is determined by which BIGIP is active for the traffic group. This will automatically change when a failover occurs.
Again on the server side of the BIGIP the the adjacent router will advertise the attached network through OSPF. Traffic leaving the BIGIP towards the server will use SNAT to change the source address to the floating IP address of the traffic group (assumes SNAT automap). Again this address is currently hosted by whichever BIGIP is currently hosting the that floating IP address. This is determined by which BIGIP is active for the traffic group. This will automatically change when a failover occurs.
There is no need to advertise specific routes for BIGIP traffic. The adjacent routers should look after all of that for you. The BIGIP's will respond based on which traffic group's they are currently hosting. This is all done at the MAC level in the attached VLANS.
Sumanta_88744Thanks Kevin, for detailed explanation. I will be using static routing in the internal server pool segment. I will have two floating VIPs per LB in the same VLAN. Servers will forward traffic to default gateway of the traffic group active on LB1. Reverse traffic will flow based on the SNAT as you mentioned. Auto last hop needs to be enabled?- Kevin_Davies_40Yes, auto last hop should always be enabled. It means you do not have to provide routes back to the client. I am surprised you have any routes at all if the servers are in the same VLAN. You only need routes if your servers are in a network elsewhere. If servers are talking to a VIP they will go to that VIP's address. If there is return traffic from a server it will go to the SNAT address. If however, your are doing forwarding virtual servers then you need to tell us as they have special requirements.
- Sumanta_88744Yes, I have forwarding vs. One for default next-hop, non-http traffic. It should follow the path received by OSPF routing protocol. The other one is for redirecting http traffic to internal server pool.
- Kevin_Davies_40Please ensure you provide this kind of critical information in the beginning. I will get back to you shortly
- Sumanta_88744Hi Kevin I have used /30 peering towards upstream/downstream routers with only self IPs and no floating. However, the active LB unit has Master status and is showing OSPF and BFD as up. But the standby LB unit shows only OSPF routes in Zebos table, bit BFD is down. Is this by design?
- Sumanta_88744Hi Experts Can anyone respond to this, please ?