topic RE: XOS ping with record-route in ExtremeSwitching (EXOS/Switch Engine)

XOS ping with record-route

M_Nees — Wed, 19 Aug 2015 16:18:00 GMT

What is the use-case for an ping the option "with record-route" ? How can use it reasonable? Command line reference do not tell anything deeper.

If i try it, i will get following output:

Slot-1 cnsha1sw001.24 # ping vr "VR-Default" continuous 10.0.8.44 from 10.64.4.1 with record-route

Ping(ICMP) 10.0.8.44: continuous packets, 8 data bytes, interval 1 second(s).
16 bytes from 10.0.8.44: icmp_seq=0 ttl=118 time=195 ms
RR:

16 bytes from 10.0.8.44: icmp_seq=1 ttl=118 time=190 ms
(same route)
16 bytes from 10.0.8.44: icmp_seq=2 ttl=118 time=185 ms
(same route)
16 bytes from 10.0.8.44: icmp_seq=3 ttl=118 time=189 ms
(same route)
^C
--- 10.0.8.44 ping statistics ---

Regards

RE: XOS ping with record-route

Rahmathullah__S — Wed, 19 Aug 2015 17:13:00 GMT

Hi,
Use of record-route displays trace route information.
The intermediate hops ip adress and its ttl value is displayed , example :

* X460-48t.22 # ping 20.20.20.20 from 10.10.10.10 with record-route
Ping(ICMP) 20.20.20.20: 4 packets, 8 data bytes, interval 1 second(s).
16 bytes from 20.20.20.20: icmp_seq=0 ttl=64 time=0.979 ms
RR: 10.10.10.10
20.20.20.20
20.20.20.20
10.10.10.10

16 bytes from 20.20.20.20: icmp_seq=1 ttl=64 time=0.314 ms
(same route)
16 bytes from 20.20.20.20: icmp_seq=2 ttl=64 time=0.306 ms
(same route)
16 bytes from 20.20.20.20: icmp_seq=3 ttl=64 time=0.354 ms
(same route)

--- 20.20.20.20 ping statistics ---
4 packets transmitted, 4 packets received, 0% loss
round-trip min/avg/max = 0/0/0 ms

-Syed

RE: XOS ping with record-route

Prashanth_KG — Thu, 20 Aug 2015 14:05:00 GMT

Key points about Record-route option:

- When a record-route option is enabled while sending an ICMP request, the internet module of the routers in the path should include its interface address in which this packet is received.
- Since the record route option is enabled in the ICMP echo request, even while forwarding the ICMP echo replies, back to the source, the routers should include their IP interfaces along the path.
- so, with record route option, we will have a round trip path unlike trace route where we know only the intermediate hops to reach the destination.

For example, consider this setup:

SRC address(10.2.1.2) RTR1 (Egress interface 10.2.0.2) -------- Ingress interface(10.2.0.1) RTR2 (egress interface 10.2.0.21)----------- ingress interface(10.2.0.22) RTR3 (Destination address 10.2.1.1)

In the above path, if I do a ping with record route from 10.2.1.2 to 10.2.1.1 without specifying the source-address, the following is the response.

ping 10.2.1.1 with record-route

Ping(ICMP) 10.2.1.1: 4 packets, 8 data bytes, interval 1 second(s).
16 bytes from 10.2.1.1: icmp_seq=0 ttl=63 time=9.536 ms
RR: 10.2.0.2
10.2.0.21
10.2.1.1
10.2.1.1
10.2.0.1
10.2.0.2

If I specify the record route from a specific source, I also see that the specified source-address is included in the recorded path.

ping 10.2.1.1 from 10.2.1.2 with record-route

Ping(ICMP) 10.2.1.1: 4 packets, 8 data bytes, interval 1 second(s).
16 bytes from 10.2.1.1: icmp_seq=0 ttl=63 time=10 ms
RR: 10.2.1.2
10.2.0.21
10.2.1.1
10.2.1.1
10.2.0.1
10.2.1.2

If I do a traceroute, i see only the hops to reach the destination.

traceroute 10.2.1.1 from 10.2.1.2

traceroute to 10.2.1.1, 30 hops max
1 10.2.0.1 1 ms 4 ms 4 ms
2 10.2.1.1 4 ms 0 ms 0 ms

Hope this clarifies!

RE: XOS ping with record-route

Prashanth_KG — Thu, 20 Aug 2015 14:08:00 GMT

I think ping with record-route option would be extremely useful when you have an asymmetric routing to a specific destination where the traffic from the source to the destination takes one path and the return traffic takes another.

RE: XOS ping with record-route

M_Nees — Thu, 20 Aug 2015 14:14:00 GMT

Thanks for your rich explanation, now i am fully understand the use-case!

RE: XOS ping with record-route

Prashanth_KG — Fri, 21 Aug 2015 09:38:00 GMT

Matthias,

Glad we could help! Explanation is documented under the article https://gtacknowledge.extremenetworks.com/articles/Q_A/How-is-PING-with-record-route-option-better-than-traceroute

RE: XOS ping with record-route

M_Nees — Fri, 21 Aug 2015 12:26:00 GMT

i think these information should be part of the recent XOS command line reference. Can you arrange that?

RE: XOS ping with record-route

Prashanth_KG — Fri, 21 Aug 2015 12:53:00 GMT

Hi Matthias,

Thank your the input. enabling the record-route (IP option 7) is a feature by itself. So, in the switch, it can be enabled all the time by the command, enable ip-option record-route. under this command, we have an explanation about this.

Snippet from the command reference guide under the command enable ip-option record-route:

Usage Guidelines
IP option record-route (IP option 7) means that each router along the path should add its IP address
into the options data.
Enabling means that the switch adds itself into the IP options header when the record route IP option is
enabled in a packet that is transiting the switch.

Under the ping command, it is just an additional parameter which can be used.
So, I believe command reference guide explains this option well and the article explains its application. Hope this helps!

RE: XOS ping with record-route

M_Nees — Fri, 21 Aug 2015 13:07:00 GMT

Whithout your last comment i do not know (and i guess many other user too) that this option have to enable on every router in the path. But this is a basically need that the ping command tell us what we want to see!.

So from my point of view in the CLI Ref a link should be set at the ping option "record-route" to the command "enable ip-option record-route".

Regards

RE: XOS ping with record-route

Prashanth_KG — Fri, 21 Aug 2015 18:01:00 GMT

Hi Matthias,

I understand your point of view. We really appreciate your feedback. I will check internally on how to add the note as you suggested in the command reference guide!

RE: XOS ping with record-route

Christina_M — Fri, 18 Sep 2015 23:06:00 GMT

Matthias,

I just wanted to let you know that, per your feedback, we updated the information about the "record-route" option in the PING command's usage guidelines. You can see the updated content here:

http://documentation.extremenetworks.com/exos_commands/EXOS_All/EXOS_Commands_All/r_ping.shtml

Thanks for your feedback!