IOS-XR ping source

[Garry Peirce]

I've an issue where the source of my pings from a router are ideally sourced from a loopback.

For many host services the source-interface command can be used to set this. (ftp,tftp,ntp,snmp etc).

However for ping/traceroute , like IOS, no such command exists and it defaults to use the sourceIP of the the interface towards the destination.

In XR though (4.3.0) I'm seeing that specifying the source by interface name seems to take ~15 seconds to resolve  ; specifying the loopback's IP is fine.

Sourcing a ping by interface name on a 7600 is immediate.

Ideally ping/traceroute could have a source-interface command as well, but in lieu of that, using the interface name would be easier than looking up the IP every time.

Anyone else seeing this delay with using an interface name?

[smilstea]

Hi Garry,

I just tested this in the lab with both the actual interface and a loopback that is on a different subnet with no issues. Can you clarify the issue you are having?

RP/0/RSP0/CPU0:ASR9006#ping 172.20.60.2 source TenGigE0/1/0/10

Fri Apr 19 05:36:34.897 UTC

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 172.20.60.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/10 ms

RP/0/RSP0/CPU0:ASR9006#

RP/0/RSP0/CPU0:ASR9006#ping 172.20.60.2 source Loopback625

Fri Apr 19 05:38:12.066 UTC

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 172.20.60.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms

RP/0/RSP0/CPU0:ASR9006#

Regards,

Sam Milstead

CSE - XR TAC

[Garry Peirce]

I found it.  The issue was related the the other part of my question.

I had not configured domain lookups to use the loopback as a source.  ;-)

Therefore I think the ping command was trying to resolve the interface name via DNS (?).

After configuring the following it's responding much more quickly.

'domain lookup source-interface loop0'

Sure would be nice to collect these source-interface commands within XR as opposed to many one-offs as

well as for enabling to do so for base services like ping/trace as well.

ex.

logging source-interface Loopback0

domain lookup source-interface Loopback0

ftp client source-interface Loopback0

tftp client source-interface Loopback0

snmp-server trap-source Loopback0

ntp

source Loopback0