Equipment (Modems,Gateways)
Modems, Gateways, and Networking Devices
Male IT Specialist Holds Laptop and Discusses Work with Female Server Technician. They're Standing in Data Center, Rack Server Cabinet is Open.
Highlighted
New Member

Network down but interface up/up

Question:

 

Using Comcast Business to to run IPsec tunnel back into network thru Cisco 1921 router. When Comcast network is down (cannot ping gateway address) interface on router stays in up/up state negating failover to back up wireless modem. Not sure why  interface on router is staying up when Comcast network is actually down...any suggestion would be appreciated.

 

 

0 Kudos
Reply
3 REPLIES 3
Highlighted
Trusted Forum Contributor

Re: Network down but interface up/up

Likely because as far as the 1921 is concerned, the PHY link to the Comcast gateway is still connected even when there are issues further on in Comcast's network. You will need to use another failover method than just detectong whether the Ciscos interface is up or down.
0 Kudos
Reply
Highlighted
Frequent Contributor

Re: Network down but interface up/up

Train wreck is on it here. The layer 2 link is up. Use hsrp to detect a down situation if you have dual cisco solutions. Also if you use a cradlepoint it's super easy, I would completely recommend.
0 Kudos
Reply
Highlighted
Frequent Contributor

Re: Network down but interface up/up

Also you will need to use object tracking with hsrp. Here's a good primer: https://mellowd.co.uk/ccie/?p=827
0 Kudos
Reply