General

How to use Extended Ping utility

Posted on by — No Comments ↓

IP header options. This prompt offers more than one option to be selected. They are:

  • Verbose is automatically selected along with any other option.
  • Record is a very useful option because it displays the address(es) of the hops (up to nine) the packet goes through.
  • Loose allows you to influence the path by specifying the address(es) of the hop(s) you want the packet to go through.
  • Strict is used to specify the hop(s) that you want the packet to go through, but no other hop(s) are allowed to be visited.
  • Timestamp is used to measure roundtrip time to particular hosts.

The difference between using the Record option of this command and using the traceroute command is that, the Record option of this command not only informs you of the hops that the echo request (ping) went through to get to the destination, but it also informs you of the hops it visited on the return path. With the traceroute command, you do not get information about the path that the echo reply takes. The traceroute command issues prompts for the required fields. Note that the traceroute command places the requested options in each probe. However, there is no guarantee that all routers (or end nodes) process the options. The default is none.

  • Loose source routing, in which a series of IP addresses for router interfaces is listed. The packet must pass through each of these addresses, although multiple hops might be taken between the addresses.
  • Strict source routing, where again a series of router addresses is listed. Unlike loose source routing, the packet must follow the route exactly. If the next hop is not the next address on the list, an error occurs.
  • Record route provides room for each router to enter the address of its outgoing interface as the packet transits so that a record is kept of all routers the packet encounters. Record route provides a function similar totrace except that the outgoing interfaces, both on the path to the destination and on the return path, are recorded.
  • Timestamp is an option similar to record route except each router also enters a timestamp: the packet not only keeps track of where it has been but also records when it was there.

All these options might be invoked by using the Extended Ping on Cisco routers. Record route is used in Example 1-1, loose source routing and timestamp are used in Example 1-3, and strict source routing is used in Example 1-4.


Example 1-1. The IOS Extended Ping utility allows the setting of the DF bit to test MTUs across a network. In this ping Output, the largest MTU of the path to destination 172.16.113.17 is 1478 octets.

R1#ping

Protocol [ip]:

Target IP address: 172.16.113.17

Repeat count [5]: 1

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]: y

Source address:

Type of service [0]:

Set DF bit in IP header? [no]: y

Validate reply data? [no]:

Data pattern [0xABCD]:

Loose, Strict, Record, Timestamp, Verbose[none]: r

Number of hops [9]:

Loose, Strict, Record, Timestamp, Verbose[RV]:

Sweep range of sizes [n]: y

Sweep min size [76]: 500

Sweep max size [18024]: 2000

Sweep interval [1]: 500

Type escape sequence to abort.

Sending 4, [500..2000]-byte ICMP Echos to 172.16.113.17, timeout is 2 seconds:

Packet has IP options:  Total option bytes= 39, padded length=40

Record route: <*> 0.0.0.0 0.0.0.0 0.0.0.0 0.0.0.0

0.0.0.0 0.0.0.0 0.0.0.0 0.0.0.0 0.0.0.0

 

Reply to request 0 (16 ms) (size 500).  Received packet has options

Total option bytes= 40, padded length=40

Record route: 172.16.192.5 172.16.113.18 172.16.113.17 172.16.113.17

172.16.192.6 172.16.192.5 <*> 0.0.0.0 0.0.0.0 0.0.0.0

End of list

 

Reply to request 1 (24 ms) (size 1000).  Received packet has options

Total option bytes= 40, padded length=40

Record route: 172.16.192.5 172.16.113.18 172.16.113.17 172.16.113.17

172.16.192.6 172.16.192.5 <*> 0.0.0.0 0.0.0.0 0.0.0.0

End of list

 

Reply to request 2 (28 ms) (size 1500).  Received packet has options

Total option bytes= 40, padded length=40

Record route: 172.16.192.5 172.16.113.18 172.16.113.17 172.16.113.17

172.16.192.6 172.16.192.5 <*> 0.0.0.0 0.0.0.0 0.0.0.0

End of list

 

Unreachable from 172.16.192.6, maximum MTU 1478 (size 2000).

Received packet has options

Total option bytes= 39, padded length=40

Record route: <*> 0.0.0.0 0.0.0.0 0.0.0.0 0.0.0.0

0.0.0.0 0.0.0.0 0.0.0.0 0.0.0.0 0.0.0.0

 

Success rate is 75 percent (3/4), round-trip min/avg/max = 16/22/28 ms

R1#

 

Example 1-3. The Cisco Extended Ping can be used to set parameters in the Options field of the IP header. In this example, loose source routing and timestamp are used.

R1#ping

Protocol [ip]:

Target IP address: 172.16.113.9

Repeat count [5]:

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]: y

Source address:

Type of service [0]:

Set DF bit in IP header? [no]:

Validate reply data? [no]:

Data pattern [0xABCD]:

Loose, Strict, Record, Timestamp, Verbose[none]: l

Source route: 172.16.113.14 172.16.113.10

Loose, Strict, Record, Timestamp, Verbose[LV]: t

Number of timestamps [ 6 ]: 2

Loose, Strict, Record, Timestamp, Verbose[LTV]:

Sweep range of sizes [n]:

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 172.16.113.9, timeout is 2 seconds:

Packet has IP options: Total option bytes= 23, padded length=24

Loose source route: <*> 172.16.113.14 172.16.113.10

Timestamp: Type 0. Overflows: 0 length 12, ptr 5

>>Current pointer<<

Time= 0

Time= 0

 

Request 0 timed out

Reply to request 1 (76 ms). Received packet has options

Total option bytes= 24, padded length=24

Loose source route: 172.16.113.13 172.16.192.6 <*>

Timestamp: Type 0. Overflows: 6 length 12, ptr 13

Time= 80FF4798

Time= 80FF4750

>>Current pointer<<

End of list

 

Request 2 timed out

Reply to request 3 (76 ms). Received packet has options

Total option bytes= 24, padded length=24

Loose source route: 172.16.113.13 172.16.192.6 <*>

Timestamp: Type 0. Overflows: 6 length 12, ptr 13

Time= 80FF4FC0

Time= 80FF4F78

>>Current pointer<<

End of list

 

Request 4 timed out

Success rate is 40 percent (2/5), round-trip min/avg/max = 76/76/76 ms

R1#
Example 1-4. Extended Ping is used here to set strict source routing in the ping packets.

R1#ping

Protocol [ip]:

Target IP address: 172.16.113.10

Repeat count [5]: 2

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]: y

Source address:

Type of service [0]:

Set DF bit in IP header? [no]:

Validate reply data? [no]:

Data pattern [0xABCD]:

Loose, Strict, Record, Timestamp, Verbose[none]: s

Source route: 172.16.192.6 172.16.113.17 172.16.113.10

Loose, Strict, Record, Timestamp, Verbose[SV]:

Sweep range of sizes [n]:

Type escape sequence to abort.

Sending 2, 100-byte ICMP Echos to 172.16.113.10, timeout is 2 seconds:

Packet has IP options: Total option bytes= 15, padded length=16

Strict source route: <*> 172.16.192.6 172.16.113.17 172.16.113.10

 

Reply to request 0 (80 ms). Received packet has options

Total option bytes= 16, padded length=16

Strict source route: 172.16.113.10 172.16.113.17 172.16.192.6 <*>

End of list

 

Reply to request 1 (76 ms). Received packet has options

Total option bytes= 16, padded length=16

Strict source route: 172.16.113.10 172.16.113.17 172.16.192.6 <*>

End of list

 

Success rate is 100 percent (2/2), round-trip min/avg/max = 76/78/80 ms

R1#

 

References:
Routing TCP/IP 1
By Jeff Doyle, Jennifer Carro