01-31-2013 06:12 AM - edited 03-04-2019 06:54 PM
Hello,
It appears that the extended ping function in a cisco router or switch has a limit of 9 hops. Is there any way to increase this?
CH-3560-6#ping
Protocol [ip]:
Target IP address: 10.150.40.60
Repeat count [5]:
Datagram size [100]:
Timeout in seconds [2]:
Extended commands [n]: y
Source address or interface: 10.181.4.6
Type of service [0]:
Set DF bit in IP header? [no]:
Validate reply data? [no]:
Data pattern [0xABCD]:
Loose, Strict, Record, Timestamp, Verbose[none]: R
Number of hops [ 9 ]: 10
Invalid Number of Hops
Loose, Strict, Record, Timestamp, Verbose[none]: R
Number of hops [ 9 ]: 12
Invalid Number of Hops
Loose, Strict, Record, Timestamp, Verbose[none]: R
Number of hops [ 9 ]:
Loose, Strict, Record, Timestamp, Verbose[RV]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.150.40.60, timeout is 2 seconds:
Packet sent with a source address of 10.181.4.6
Solved! Go to Solution.
01-31-2013 08:08 AM
Hi,
it's not the Extended Ping, just the Record option.
But no chance to increase, I'm afraid.
And not only due to Cisco IOS implementation.
RFC 1812 (https://tools.ietf.org/html/rfc1812#section-4.3.3.6 ) says:
" If a Record Route and/or Timestamp option is received in an ICMP Echo
Request, this option (these options) SHOULD be updated to include the
current router and included in the IP header of the Echo Reply
message, without truncation. Thus, the recorded route will be for
the entire round trip."
If you look at the IP header structure (http://en.wikipedia.org/wiki/IPv4#Header ), you will see there is only space for 9 IP addresses left in the IP header Options field.
HTH,
Milan
Message was edited by: MILAN KULIK
01-31-2013 07:27 AM
Hi,
There is no way to increase that value.
And also please check following past-discussion.
01-31-2013 07:35 AM
Hello Adil,
the extended ping number of hops is limited to 9 router hops.
within 9 router hops the extended ping provides the path for the transmit and return path
You can use traceroute from A to B and from B to A to find out the paths in the two directions.
Hope to help
Giuseppe
01-31-2013 08:08 AM
Hi,
it's not the Extended Ping, just the Record option.
But no chance to increase, I'm afraid.
And not only due to Cisco IOS implementation.
RFC 1812 (https://tools.ietf.org/html/rfc1812#section-4.3.3.6 ) says:
" If a Record Route and/or Timestamp option is received in an ICMP Echo
Request, this option (these options) SHOULD be updated to include the
current router and included in the IP header of the Echo Reply
message, without truncation. Thus, the recorded route will be for
the entire round trip."
If you look at the IP header structure (http://en.wikipedia.org/wiki/IPv4#Header ), you will see there is only space for 9 IP addresses left in the IP header Options field.
HTH,
Milan
Message was edited by: MILAN KULIK
02-01-2013 03:12 AM
Hello Milan,
very good finding it explains the root cause of the limitation with the record option in extended ping.
Best Regards
Giuseppe
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