# Active/Standby with OSPF

**URL:** <https://community.a10networks.com/t/active-standby-with-ospf/208>\
**Category:** System\
**Created:** [June 20, 2013, 9:23am UTC](https://community.a10networks.com/t/active-standby-with-ospf/208 "2013-06-20T09:23:55Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![nabromov](https://avatars.discourse-cdn.com/v4/letter/n/22d042/32.png) [@nabromov](https://community.a10networks.com/u/nabromov)\
**Post date:** [June 20, 2013, 9:23am UTC](https://community.a10networks.com/t/active-standby-with-ospf/208/1 "2013-06-20T09:23:55Z")

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Dear All,

I would like to make two AX500’s to work in Active/Standby mode with OSPF, where the default route is announced only by the active A10 in the pair. Is that possible?

Please find the attached example topology.

Thank you in advance.

Best Regards,  
Nik

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex002/uploads/a10_community/original/1X/bb9f186d33804d3044a0374e589f49fdf3be1328.png) [@system](https://community.a10networks.com/u/system)\
**Post date:** [July 1, 2013, 5:27pm UTC](https://community.a10networks.com/t/active-standby-with-ospf/208/2 "2013-07-01T17:27:01Z")

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Hello  
the short is is Yes it is definitely possible

The AX device uses HA-aware VIPs, floating IPs, IP NAT pools, and IP  
range lists with route redistribution to achieve HA-aware dynamic routing.  
However, by default, the OSPF protocol on the AX device is not aware of  
the HA state (Active or Standby) of the AX device. Consequently, following  
HA failover of an AX device, other OSPF routers might continue forwarding  
traffic to the Standby AX device (the former Active AX device), instead  
of the new Active AX device.  
Note: In Layer 3 inline mode, all VLANs on the AX device participate in OSPF  
routing by default.  
You can assign an additional cost to an AX device’s OSPF interfaces when  
the HA status for any group on the device is Standby. If failover of one or  
more HA groups from Active to Standby occurs, the AX device does the  
following:  
• Updates the cost of all its OSPF interfaces  
• Sends Link-State Advertisement (LSA) updates to its OSPF neighbors  
advertising the interface cost change

for additional configuration information you can check the AX config guide section “Configuring OSPF-Related HA Parameters”