Cisco XRV9000 no DNS resolution ?!

huud · ‎08-31-2023

Hi all,

I'm moving from OPNSense to Cisco XRv9000, and am trying to get internet access to the Cisco router. I can ping 8.8.8.8 but pinging www.google.com does not work.

RP/0/RP0/CPU0:xrv1#ping 8.8.8.8
Thu Aug 31 13:32:21.410 UTC
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 8.8.8.8, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 13/14/15 ms

RP/0/RP0/CPU0:xrv1#ping www.google.com
Thu Aug 31 13:31:50.829 UTC
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2a00:1450:400b:c03::68, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

This is from a different machine on the same network as the Cisco, DNS seems to be working fine.

Windows IP Configuration

   Host Name . . . . . . . . . . . . : DESKTOP-OVF6PQC
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Ethernet0:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Intel(R) 82574L Gigabit Network Connection
   Physical Address. . . . . . . . . : 00-0C-29-9E-BA-50
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::a537:55cd:da00:8e0d%13(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.11.221(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.11.2
   DHCPv6 IAID . . . . . . . . . . . : 100666409
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-2C-09-DB-DD-00-0C-29-9E-BA-50
   DNS Servers . . . . . . . . . . . : 192.168.11.5
   NetBIOS over Tcpip. . . . . . . . : Enabled
PS C:\Windows\system32> ping www.google.com

Pinging www.google.com [209.85.202.99] with 32 bytes of data:
Reply from 209.85.202.99: bytes=32 time=58ms TTL=127
Reply from 209.85.202.99: bytes=32 time=51ms TTL=127
Reply from 209.85.202.99: bytes=32 time=20ms TTL=127
Reply from 209.85.202.99: bytes=32 time=27ms TTL=127

Ping statistics for 209.85.202.99:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 20ms, Maximum = 58ms, Average = 39ms

Cisco Configuration

RP/0/RP0/CPU0:xrv1#show running-config
Thu Aug 31 13:29:24.825 UTC
Building configuration...
!! IOS XR Configuration 7.2.1
!! Last configuration change at Thu Aug 31 13:24:27 2023 by admin
!
hostname xrv1
domain name vlab.lab
domain name-server 192.168.11.5
domain lookup source-interface MgmtEth0/RP0/CPU0/0
username admin
 group root-lr
 group cisco-support
!
call-home
 service active
 contact smart-licensing
 profile CiscoTAC-1
  active
  destination transport-method http
 !
!
interface MgmtEth0/RP0/CPU0/0
 ipv4 address 192.168.11.100 255.255.255.0
!
interface GigabitEthernet0/0/0/0
 ipv4 address 192.168.1.100 255.255.255.0
!
interface GigabitEthernet0/0/0/1
 shutdown
!
interface GigabitEthernet0/0/0/2
 shutdown
!
interface GigabitEthernet0/0/0/3
 shutdown
!
interface GigabitEthernet0/0/0/4
 shutdown
!
interface GigabitEthernet0/0/0/5
 shutdown
!
interface GigabitEthernet0/0/0/6
 shutdown
!
router static
 address-family ipv4 unicast
  0.0.0.0/0 192.168.11.2
 !
!
ssh server v2
end

Not sure what's missing.

b.winter · ‎08-31-2023

If you would look at the PING output, you would see, that you are trying to ping an IPv6 address.
If you don't use IPv6, then it probably won't work.

huud · ‎08-31-2023

Thanks for pointing that out, I see it now.

I'm not using IPv6, and have disabled it on all ports, still the same reply but on a different IPv6 address.

Sending 5, 100-byte ICMP Echos to 2a00:1450:400b:c01::6a, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

huud · ‎08-31-2023

I have to use ping ipv4 to get a success reply over ipv4..