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Author Topic: ICMP (Ping) Packets dropped by 4548GT-PWR and not 5510-24T  (Read 4407 times)

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Offline scottm264

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ICMP (Ping) Packets dropped by 4548GT-PWR and not 5510-24T
« on: July 17, 2013, 10:44:07 AM »
Hello All,
  I sure appreciate this forum as it seems to be the only knowledgebase for Nortel Switching products that I can find. 
I have:
two 4548GT-PWR's  HW:05 FW:5.1.0.8 SW:v5.1.2.004 BN:04
one 4524GT-PWR HW:01 FW:5.3.0.3 SW:v5.3.0.008 BN:08
one 5510-24T HW:03 FW:5.0.0.3 SW:v5.0.4.010 BN:00.
I have two fully patched Windows Server 2008R2 servers (serverA and serverB) that are virtualized on the same fully patched ESXi 5.1 Host.
I am not currently experiencing any visible issues communicating with or through the switches, but I noticed a strange situation a few months ago that I have not been able to get to the bottom of. 
I pinged both the 4548's and the 4524 from serverA and noticed packet loss.  It ranges between 15-40% packet loss. The packet loss is immediate and seems to come in waves, where it pings <1ms for 6-10 round trips and then 'Request timed out.' the next 3 or 4 packets.
If I do the same test from serverB I see perfect <1ms returns from all switches. 
Now you might say, clearly it is serverA to blame... well not so fast, as I can ping other devices from serverA including the Nortel 5510-24T that is behind the 4548 and 4524 without any loss . Can someone tell me why my 45xx series switches might be discriminating the traffic from this server and what I can do or ignore to resolve this issue?  ???
Thanks in advance!
-Scott
« Last Edit: July 17, 2013, 10:46:12 AM by scottm264 »


Offline Flintstone

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Re: ICMP (Ping) Packets dropped by 4548GT-PWR and not 5510-24T
« Reply #1 on: July 17, 2013, 11:48:30 AM »
Hi scottm264 and welcome to the forum,

I would try and use a Sniffer to capture any packets and see what is happening?

CheerZ and good luck

Offline Michael McNamara

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Re: ICMP (Ping) Packets dropped by 4548GT-PWR and not 5510-24T
« Reply #2 on: July 18, 2013, 03:41:26 PM »
Hi Scott and welcome to the forums!

As you probably already know you shouldn't be experiencing such a drastic amount of packet loss. Is this a configuration or operational issue? It's hard to answer in one reply because it could be load related, or it could be switch software related. The versions of software that you are running are quite old. Are you utilize FC or iSCSI based storage? The iSCSI load could be related to the problem... are you trunking multiple VLANs into the VM environment? Perhaps a duplex mis-match somewhere between the VM hosts and the switches? Do you have multiple NICs in the VMware portgroups? There are so many questions I could ask, however, the most important one would be this. Are you experiencing any packet loss between your desktop/laptops and the VM guests. If so then you should probably continue your search, else you might decide to just ignore it.

Good Luck!
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Offline scottm264

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Re: ICMP (Ping) Packets dropped by 4548GT-PWR and not 5510-24T
« Reply #3 on: July 23, 2013, 03:07:13 PM »
Hi Michael,
  Thanks for your detailed reply. 
-It does not seem to be load related, as it behaves the same at any hour, weather users are present or not. 
-No iSCSI or FC at this site.
-We are using VLAN's, but they are not Trunked (I assume you mean bonding more than one interface together).
-As for the Speed/Duplex, If we are Auto negotiating at 1000/Full, can I leave things at AUTO in this case?
--We are not seeing packet loss anywhere else at this time.  Client to Server communications appear to be operating normally. 
--I can put a request in to purchase a Service Agreement to upgrade the Firmware.  Do you think there are enough performance and bug-fixes to warrant the effort in upgrading all of these switches firmware to the latest revisions?  Is there any way to see the Change-logs/Release Notes for the Firmware updates without purchasing the Service Agreement?

Offline Telair

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Re: ICMP (Ping) Packets dropped by 4548GT-PWR and not 5510-24T
« Reply #4 on: July 23, 2013, 05:53:51 PM »
If you are using gigabit copper, the only official way to connect at gig speed is to use the auto-negotiation function on the ports.  I know at one point Cisco told people to not use auto-negotiation, not sure if they still say that.  As long as both sides agree on 1000/Full when set to auto, you are fine.

Yes, upgrading the software on 4000's and 5000's is very much worth it.  Many new features have been added over the years as well as many bugs have been fixed.  It would be a good idea to get at least a "software maintenance" agreement which gives you the ability to download new code.

Offline Michael McNamara

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Re: ICMP (Ping) Packets dropped by 4548GT-PWR and not 5510-24T
« Reply #5 on: July 23, 2013, 08:07:40 PM »
You can view almost every software release on my blog;

https://www.google.com/#output=search&sclient=psy-ab&q=site:blog.michaelfmcnamara.com+software+release&oq=site:blog.michaelfmcnamara.com+software+release

Or you could also check search support.avaya.com, I believe the release notes are available without charge.

Cheers!
We've been helping network engineers, system administrators and technology professionals since June 2009.
If you've found this site useful or helpful, please help me spread the word. Link to us in your blog or homepage - Thanks!