GNS3 lab - Having difficulties translating DNS between two Routers.
CompUBug
Member Posts: 46 ■■□□□□□□□□
in CCNA & CCENT
I have three routers and two switches.
R1 > SW1 > R2 > SW2 > R3
R3 is the DNS Server
R1 is the DNS client
R2 does not have ip domain-lookup configured (and I don't think it should.)
Here is the DNS configuration for R1:
and for R3:
[FONT=&]When I try to ping R3 or R2 from R1 it just times out and I also get a repeating error on R3 that says:[/FONT]
When I remove the ip domain-name flackboxA.lab by using the command no ip domain-name flackboxA.lab and then try to ping R3 or R2 from R1, it resolves and pings perfectly fine but when re-adding it, it once again stops working:[/FONT]
Any idea as to whats wrong?[/FONT]
R1 > SW1 > R2 > SW2 > R3
R3 is the DNS Server
R1 is the DNS client
R2 does not have ip domain-lookup configured (and I don't think it should.)
Here is the DNS configuration for R1:
[COLOR=#29303B][FONT=&]R1(config)#ip domain-lookup[/FONT][/COLOR] [COLOR=#29303B][FONT=&]R1(config)#ip name-server 10.10.20.1[/FONT][/COLOR] [COLOR=#29303B][FONT=&]R1(config)#ip domain-name flackboxA.lab[/FONT][/COLOR] [COLOR=#29303B][FONT=&]R1(config)#ip domain-list flackboxB.lab[/FONT][/COLOR]
and for R3:
[COLOR=#29303B][FONT=&]R3(config)#ip domain-lookup[/FONT][/COLOR] [COLOR=#29303B][FONT=&]R3(config)#ip dns server[/FONT][/COLOR] [COLOR=#29303B][FONT=&]R3(config)#ip domain-name flackboxA.lab[/FONT][/COLOR] [COLOR=#29303B][FONT=&]R3(config)#ip domain-list flackboxB.lab[/FONT][/COLOR] [COLOR=#29303B][FONT=&]R3(config)#ip host R1 10.10.10.1[/FONT][/COLOR] [COLOR=#29303B][FONT=&]R3(config)#ip host R2 10.10.10.2[/FONT][/COLOR] [COLOR=#29303B][FONT=&]R3(config)#ip host R3 10.10.20.1[/FONT][/COLOR]
[FONT=&]When I try to ping R3 or R2 from R1 it just times out and I also get a repeating error on R3 that says:[/FONT]
[COLOR=#29303B][FONT=&]% Warning: Invalid name-server 10.10.20.1 (it's this router) - configuring anyway R3(config)# *Mar 1 00:09:06.891: %FIB-4-FIBCBLK: Missing cef table for tableid 65535 during CEF samecable event R3(config)# *Mar 1 00:09:12.163: %FIB-4-FIBCBLK: Missing cef table for tableid 65535 during CEF samecable event[/FONT][/COLOR][FONT=&]
When I remove the ip domain-name flackboxA.lab by using the command no ip domain-name flackboxA.lab and then try to ping R3 or R2 from R1, it resolves and pings perfectly fine but when re-adding it, it once again stops working:[/FONT]
[COLOR=#29303B][FONT=&]R1#ping R3[/FONT][/COLOR] [COLOR=#29303B][FONT=&]Translating "R3"...domain server (10.10.20.1) [OK][/FONT][/COLOR] [COLOR=#29303B][FONT=&]Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.10.20.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 28/36/48 ms R1#conf t Enter configuration commands, one per line. End with CNTL/Z. R1(config)#ip domain-name flackboxA.lab R1(config)#do ping R3[/FONT][/COLOR] [COLOR=#29303B][FONT=&]Translating "R3"...domain server (10.10.20.1) % Unrecognized host or address, or protocol not running.[/FONT][/COLOR][FONT=&]
Any idea as to whats wrong?[/FONT]
Comments
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CompUBug
Member Posts: 46 ■■□□□□□□□□
I figured it out...
I forgot to add the domain to the host list in R3.. The DNS server[COLOR=#29303B]host R1.flackboxA 10.10.10.1 host R2.flackboxA 10.10.10.2 host R3.flackboxA 10.10.20.1
[/COLOR]