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Cisco 837 ADSL router won't import ISP DNS servers into DHCP?

whiteford
Level 1
Level 1

Hi, sorry for these 3 simple questions I'm sure.

1.) I have a Cisco 837 for my home ADSL, it all works but I had to manually add the DNS servers from my ISP into the DHCP pool, is this normal or should it be automatic?

2.) What command can I use to find out my external IP?

3.) What command can I use to show what ADSL line speed I'm getting?

Many thanks

1 Accepted Solution

Accepted Solutions

paolo bevilacqua
Hall of Fame
Hall of Fame

Correct, it won't import dhcp server in dhcp, so far no config is possible to do so.

Either live with the server statically dns, or configiure the router as dns server:

"ip dns server"

"ip domain lookup"

set router's address in dhcp, and will do dns in there.

Other Qs is show ip interface brief" and "show dsl interface".

Hope this helps, please rate post if it does!

View solution in original post

10 Replies 10

paolo bevilacqua
Hall of Fame
Hall of Fame

Correct, it won't import dhcp server in dhcp, so far no config is possible to do so.

Either live with the server statically dns, or configiure the router as dns server:

"ip dns server"

"ip domain lookup"

set router's address in dhcp, and will do dns in there.

Other Qs is show ip interface brief" and "show dsl interface".

Hope this helps, please rate post if it does!

Thanks does "ip dns server"

"ip domain lookup" getting the settings from my ISP?

Yes if you have "ppp ipcp dns request" under dialer interface.

As a recognition to those providing answers, please rate useful posts with the scrollbox below!

Thanks, that worked.

1.) What command would I use to show the ISP's DNS servers, the commands above don't show this.

2.) How would I allow telnet and SDM from an external host? I have there IP.

1. "show ip name-server"

2. access is always permitted unless blocked by ACLs, by means of "access-class" under "vty" for telent, and "ip http access-class" for SDM.

Hope this helps, please rate post if it does!

Hi,

"show ip name-server" doesn't appear to be an option for me.

I need to allow any local address to access the SDM and telnet and an external ip of 1.2.3.4, would it look like this?

access-list 50 permit 192.168.2.10

access-list 50 permit 1.2.3.4 and so on

ip http access-class 50

line vty 0 4

access-class 50 in

What does "ip inspect" mean?

Hi,

"show ip name-servers" and 'sh ip domain" are hidded commands in recent IOS, what are you using ?

The acl appears ok.

Thanks, here is a "sh ver"

Cisco IOS Software, C837 Software (C837-K9O3Y6-M), Version 12.4(5a), RELEASE SOFTWARE (fc3)

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 1986-2006 by Cisco Systems, Inc.

Compiled Sat 14-Jan-06 01:43 by alnguyen

ROM: System Bootstrap, Version 12.2(8r)YN, RELEASE SOFTWARE (fc1)

H0m3 uptime is 2 hours, 23 minutes

System returned to ROM by reload at 16:34:45 UTC Sun Nov 11 2007

System restarted at 16:36:48 UTC Sun Nov 11 2007

System image file is "flash:c837-k9o3y6-mz.124-5a.bin"

Also what does the "ip inspect" command do, I see sample using this?

Hi,

in 12.4(11)T or XJ4 is there.

ip inspect is part of IOS firewall, that is not often wanted as using nat is FW in itself.

Good luck

Thanks, does that mean I don't need to use the firewall and just hide behind Nat? Is the best practice?

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