Cisco ISR4431 connected to ONT
echcomp
Enthusiast - Level 1

Hello all. I have a question regarding the following configuration. Maybe someone may have implimented a similar setup and got it to work..... The following is my topology that work:

Internet-------ONT------Cisco-ISR4435------LAN-------Clients.....

Cisco Router Configuration #1 - point to next hop default gateway via the interface with the "ip route 0.0.0.0 0.0.0.0 int g0/0/0" configured.   This causes serious connectivity issues in the network. Hundreds of outside networks in the ARP Table

Cisco Router Configuration #2 - points to specific next hop defaullt  gateway address with the "iproute 0.0.0.0 0.0.0.0 x.x.x.x" configured.  this works great.. no connectivity issues  and only WAN DHCP network and local address in the ARP Table

Here is the question: When the DHCP address in Configuration #2 changes then the configured gateway address is invalid and this now breaks the network. Does Verizon provide a reserved address so I could keep the same IP and default network upon lease expiration and renewal? 

 How does it work for their Actiontec or Quantum Gateway routers when they receive a new lease since the ONT doesn't provide it? When the wan address changes they have to get a new specific default gateway for the next hop.

Thanks in advance for any help or insight that could help solve this problem..

Regards,

ECH 

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echcomp
Enthusiast - Level 1

Updating everyone on this post.  I would like to give credit to "gadetboy", one of the forum members on DLS Reports for leading me in the right direction in finding a solution that address this issue. any member on this formum looking to use a Cisco Router as a gateway  need to add this command  in there configuration "i p route 0.0.0.0 0.0.0.0 dhcp". What this statement is basically saying forward  traffic to the WAN IP and Default Gateway learned from DHCP. Further research can be done on "Cisco Community" forum if you enter the command in the search box of any browser.

Hope this will help the next person running into a similar issue as it  has helped me.... 

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echcomp
Enthusiast - Level 1

Updating everyone on this post.  I would like to give credit to "gadetboy", one of the forum members on DLS Reports for leading me in the right direction in finding a solution that address this issue. any member on this formum looking to use a Cisco Router as a gateway  need to add this command  in there configuration "i p route 0.0.0.0 0.0.0.0 dhcp". What this statement is basically saying forward  traffic to the WAN IP and Default Gateway learned from DHCP. Further research can be done on "Cisco Community" forum if you enter the command in the search box of any browser.

Hope this will help the next person running into a similar issue as it  has helped me....