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Unable to connect my Cisco CMTS to virtual server

Hey!,

 

I am making my final thesis about Cisco uBR10012 CMTS-system and its deployment for Metropolia University of Applied Scienses here in Finland. I would have one question regarding this system as I have been kinda stuck for a while. For uBR10012 to work correctly with cable modems it needs DHCP-server, ToD-server and also TFTP-server to send configuration files to cable modems. I have these services on CentOS virtual server and I have configured Extreme Summit X450 switch to work between this virtual server and uBR10012-system (and also providing internet access to CMTS). My problem is that for some reason uBR10012 can't access my virtual server and so it can't get cable modems online. uBR10012 pings perfectly with the Extreme switch ( and other way around) but can't ping virtual server over the switch. Also tried to ping CMTS from virtual server and didn't work. Virtual server pings Extreme switch perfectly. I am kinda lost where the problem could be. Would really appreciate for any suggestions.

 

Added logs of CMTS and Extreme ad combined file to this post. IP for virtual server is 10.95.250.75

3 REPLIES
Hall of Fame Super Gold

Re: Unable to connect my Cisco CMTS to virtual server

If ping does not work in either direction between the devices then it suggests that there may be a routing issue. Am I correct in assuming that the address of your virtual server is 10.95.250.75? If so please do show ip route on the CMTS and see if there is a route to that subnet. Also check on the virtual server and see if it has a route to the address of the CMTS.

 

HTH

 

Rick

Community Member

Re: Unable to connect my Cisco CMTS to virtual server

Yeah. Virtual server has ip of 10.95.250.75. Problem still is that if I use the same port on Extreme (that I have normally connected to CMTS) with my PC it manages to ping virtual server. This of course suggests that I have some wrong configurations on CMTS too but even with this setup the virtual server doesn't ping the PC so it doesn't change that situation. Current ip routes that virtual server shows with ip route command are:

10.95.250.0/23 dev eth0 proto kernel scope link src 10.95.250.75

169.254.0.0/16 eth0 scope link metric 1002 default via 10.95.251.254 dev eth0

 

I created vlan named CMTS on Extreme with ip address of 10.94.70.254 and it gives ip of 10.94.70.100 via DHCP to CMTS.  CentOS Virtual server pings ping of Extreme (10.94.70.254) but doesn't ping of CMTS (10.94.70.100) trough Extreme.

 

 

 

 

Hall of Fame Super Gold

Re: Unable to connect my Cisco CMTS to virtual server

Are you saying that the only routes known on the virtual server are these

10.95.250.0/23 dev eth0 proto kernel scope link src 10.95.250.75

169.254.0.0/16 eth0 scope link metric 1002 default via 10.95.251.254 dev eth0

 

That is unexpected because it does not show a route to the subnet of CMTS and does not show a default route.

 

I asked you for the output of show ip route on the CMTS. You have not yet provided that.

 

HTH

 

Rick

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