Strange Ping Fault?

[Anonymous user]

Hello,

I have multiple USP's that are currently acting strange, the power part is fine, just random drops of network management, they are on the default switch vlan (50) all switches can be accessed and pinged from any PC and routing seems fine, given I can access switches ect from a different vlan while the switch is on 50.

network management IP can ping sometimes, and oddly when I made random changes to the edge switch they are plugged in it does sometimes ping then will go to unable to ping for ages, sometimes it will just come back to pinging then drop again, trace route does not get anywhere, the core switch (HP) can see the mac address and ARP table has the IP address correct, tested cables ect and all good.

Just to add to this, I have configured a windows laptop with the same static IP and plugged it into the same network cable that would go into the UPS and can ping it happy as day, no drops ect, but when I plug the UPS in, it is hit and miss, sometimes it will work for 5 mins? longer sometimes then drops, sometimes just won't work.

I have rebooted the edge switch and even the core just to be on the safe side, but it is very strange that I can ping a different end device without issue but once the UPS goes back in I get this random drop, we have 5 x APC smart 1500 that seem to do this, interesting the APC Smart 3000 all appear ok and stable (they don't seem to drop)

my logic here is my vlan must be correct, because I can ping everything from .1 to the last IP minus a few IPs that are the UPSs, sometimes they randomly come back up ping wise, then drop, other times they just never come up, no web access ect, I have even switched the IP address on one and this did ping then drop again, the core switch appears to be able to always ping the IP even when another edge device cant, but it is very strange as if this was a issue effecting the VLAN routing it would cause all types of alerts as other UPSs are on the same physical edge device, all edge switches are on the VLAN too.

Part of me thinks this is a routing issue? but the fact a laptop using the same cables, same IP is always working and good, but UPS drops. kinda suggests the edge device? but it is strange

Any suggestions? 🙂

[BillP]

Hi Paul,

My suspicion is that this is network related.

What you need to do is put a laptop on the same L2 subnet and switch as the UPSs and ping them, if that works then the there is no issue with the NMCs, next start moving the laptop up the stack (edge-intermediate-core-alternative edge) until the problem appears and then investigate what's in between.

Just a not about the different UPSs working and not working all Smart-UPS/Symmetra use the same NMCs doesn't matter if they're  a 1K, 3K or a 250 PX2.

-Gavan

[Anonymous user]

Hello,

Currently I have a laptop plugged in via the same cable that would provide the network management for the UPS, configured in the same way, same IP, Subnet, gateway, DNS, have been and can ping this perfectly, I agree it feels like a network / route issue, but it is very very odd that I can ping my laptop without issue, plus I have other devices on the same VLAN on the same edge switch that are fine, but maybe it is a fault with the switch unit? strange.

Paul.

[Malvineous_apc · Accepted solution]

DHCP problem?  Have you tried swapping management cards between the working UPSes and the ones with the problem, to confirm whether it's a problem with the management card or not?