Lost packet in an ping between Cisco to Riverstone Router, but viceversa no

[jibar]

Hi,

I need your help to explain me the next behavior.

I have interconnected an Cisco Router with an

RiverStone Router, i see the

next:

1. When i execute an ping from the cisco router to RS

router, i see an path

with lost of packets, this with certain frecuency.

2. When i execute the ping from the cisco router to

CPE, through Riverstone

router, all the packets are the succeful.

I need some explain at this !!!

Thanks

Jesus Ibar

[Richard Burts]

Jesus

If we had a little more detail we might be able to give better answers. It would help to know whether the Cisco and the Riverstone are directly connected or are there other network devices in between. It would also help to know what the frequency of packet loss is (is it a regular pattern or an irregular pattern, is it every other packet, one out of every three, one out of every four, or what).

Without knowing those details I can think of two possible explanations. One possibility is that the Riverstone may be rate limiting its responses to ping. I do not have any direct experience with Riverstone so I can not speak from experience. But I know that Cisco does rate limit some of its responses with ICMP. Perhaps the Riverstone limits its responses to ping when it is the destination (causing some packet loss) but when it is forwarding to some destination it forwards all of the ping packets.

Another possibility is that the Cisco (or some other device along the data path) may have two routes in its table for the Riverstone but only one of the paths actually works, so there is some packet loss. But it has a single entry in its table for the other destination, so all of the packets are correctly routed.

It might help if you would post the output of traceroute from the Cisco to the Riverstone and traceroute to the other destination.

HTH

Rick

[jibar]

Hi Rick

Thanks for your comments.

I have been collecting these patterns:

*100 pings de 100 bytes from the CISCO to

RIVERSTONE(lost each 14

pings)

PE_Mty#ping vrf SONUS-VOIP ip 192.168.57.2 repeat 100

size 100

Type escape sequence to abort.

Sending 100, 100-byte ICMP Echos to 192.168.57.2,

timeout is 2 seconds:

!!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!

Success rate is 94 percent (94/100), round-trip

min/avg/max = 1/4/96 ms

PE_Mty#

*100 pings of 200 bytes from the CISCO to RIVERSTONE

(double size that the previous), lost each 7 pings.

PE_Mty#ping vrf SONUS-VOIP ip 192.168.57.2 repeat 100

size 200

Type escape sequence to abort.

Sending 100, 200-byte ICMP Echos to 192.168.57.2,

timeout is 2 seconds:

!!!!!!!!.!!!!!!!.!!!!!!!.!!!!!!!.!!!!!!!.!!!!!!!.!!!!!!!.!!!!!!!.!!!!!!!.!!!!!!!.!!!!!!!.!!!!!!!.!!!

Success rate is 88 percent (88/100), round-trip

min/avg/max = 1/2/20 ms

PE_Mty#

*100 pings of 400 bytes from the CISCO to RIVERSTONE

(4 times of the original), lost each 4 pings:

PE_Mty#ping vrf SONUS-VOIP ip 192.168.57.2 repeat 100

size 400

Type escape sequence to abort.

Sending 100, 400-byte ICMP Echos to 192.168.57.2,

timeout is 2 seconds:

!!!!.!!!!.!!!!.!!!!.!!!!.!!!!.!!!!.!!!!.!!!!.!!!!.!!!!.!!!!.!!!!!!.!!!!.!!!!.!!!!.!!!!.!!!!.!!!!.!!!

Success rate is 81 percent (81/100), round-trip

min/avg/max = 1/1/8 ms

*Ping from the CISCO to CPE (through from the same

Riverstone),

here, not lost packets !!!

PE_Mty#ping vrf SONUS-VOIP ip 10.6.5.10 repeat 100

size 100

Type escape sequence to abort.

Sending 100, 100-byte ICMP Echos to 10.6.5.10, timeout

is 2 seconds:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Success rate is 100 percent (100/100), round-trip

min/avg/max = 1/1/4

ms

PE_Mty#ping vrf SONUS-VOIP ip 10.6.5.10 repeat 100

size 200

Type escape sequence to abort.

Sending 100, 200-byte ICMP Echos to 10.6.5.10, timeout

is 2 seconds:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Success rate is 100 percent (100/100), round-trip

min/avg/max = 1/1/4

ms

PE_Mty#ping vrf SONUS-VOIP ip 10.6.5.10 repeat 100

size 400

Type escape sequence to abort.

Sending 100, 400-byte ICMP Echos to 10.6.5.10, timeout

is 2 seconds:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Success rate is 100 percent (100/100), round-trip

min/avg/max = 1/1/8

ms

thanks.

Jesus Ibar

[jibar]

Rick,

Searching in Internet and Riverstone, we found the next document: Ping rate-limiting feature added in 7..x and newer

Ref: http://rstone.riverstonenet.com/hoth%2Dpub/techbltn/tb0096%2D9.html

Here explain this issue, we apply the workaround and the packet lost, was solved:

Before:

PE_Mty#ping vrf SONUS-VOIP

Protocol [ip]:

Target IP address: 192.168.57.2

Repeat count [5]: 1000

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]:

Sweep range of sizes [n]:

Type escape sequence to abort.

Sending 1000, 100-byte ICMP Echos to 192.168.57.2, timeout is 2 seconds:

!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!

!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!

!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.

!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!!.!!!!!!!!!!!!

Success rate is 93 percent (932/1000), round-trip min/avg/max = 1/3/272 ms

PE_Mty#

After of apply the workaround:

PE_Mty#ping vrf SONUS-VOIP

Protocol [ip]:

Target IP address: 192.168.57.2

Repeat count [5]: 1000

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]:

Sweep range of sizes [n]:

Type escape sequence to abort.

Sending 1000, 100-byte ICMP Echos to 192.168.57.2, timeout is 2 seconds:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Success rate is 100 percent (1000/1000), round-trip min/avg/max = 1/1/4 ms

PE_Mty#

Thanks for all.

Jesus Ibar

[Richard Burts]

Jesus

I am glad that you have found the answer and found a workaround. I had a feeling from the description of the symptoms that rate limiting was a likely answer, but I had not yet found anything on the Riverstone web site that confirmed that they do rate limit ping. I am glad that you found it.

HTH

Rick