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Cisco 2921 ISR Router not picking up IP Address from ISP

Ian Sully
Level 1
Level 1

I really need help, I have a Cisco 2921 Router that I am trying to use as an internet router. I have my modem connected to a Cisco Catalyst 3750 switch, the WAN is on a special VLAN, I have a home router (which I am trying to replace) connected to the WAN VLAN as well, and I have the 2921 router connected to that VLAN as well on port Gigabit Ethernet 0/0. My ISP is Cable One (now Sparklight). I have posted this .txt file for reference to what the router is doing. If someone can help me, please let me know. Thank you.

Ian 

3 Replies 3

Joseph W. Doherty
Hall of Fame
Hall of Fame

Don't know if this the case with your cable provider, but some "latch" on to the MAC.  If that's the case, you'll might be able to reset that by doing a power cycle on your cable model or if that doesn't work, have the router use the same MAC as the prior device.

Hello,

 

I am not clear on your topology. Does it look like this ?

 

ISP Modem --> Catalyst --> Home Router

                                      --> Cisco router

 

What if you take the switch out and connect the Cisco router directly to the modem ? What us the purpose of the switch ? Either way, post the full running configs of both the router and the switch.

 

Hello

So you have wan rtr and 2921 rtr connected to the same vlan on the switch - what exactly are you trying to achieve?


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Kind Regards
Paul
Review Cisco Networking products for a $25 gift card