We have an HMC which we have been having issues talking to.
This all started when we moved offices, although everything is plugged into the core exactly like it was in our old office.
Here is what I have found so far.
1) When attempting to ping 192.168.1.218 from vlan6 (our user vlan), the first reply was successful, but the other three timed out, as did subsequent tries.
2) when attempting to ping 192.168.1.218 from vlan4 (our server vlan) it appears to be very hit or miss.
3) when attempting to tracert to 192.168.1.218 from vlan6 (our user vlan), the first hop it hits is 172.18.6.1 (which is the gateway of vlan 6 and the vlan 6 interface on the core)
The second hop is 192.168.1.213 (which is very odd)
4) when attempting to tracert to 192.168.1.218 from vlan4 (our server vlan), the first hop it hits is 192.168.1.213 (which is very odd)
5) when checking the arp on a windows server, I see (This is what it should look like)
Interface: 192.168.1.131 --- 0xb
Internet Address Physical Address Type
(unimportant information redacted)e
192.168.1.213 5c-f3-fc-eb-37-3f dynamic
192.168.1.218 00-14-5e-fa-f9-4a dynamic
---sometimes, and this other times (this is what it looks like when we are having issues communicating with the HMC)
Interface: 192.168.1.131 --- 0xb
Internet Address Physical Address Type
(unimportant information redacted)
192.168.1.213 5c-f3-fc-eb-37-3f dynamic
192.168.1.218 5c-f3-fc-eb-37-3f dynamic
6) when I checked the arp on the core, I see
CORE# show arp
IP ARP table
IP Address MAC Address Type Port
--------------- ----------------- ------- ----
(unimportant information redacted)
192.168.1.213 5cf3fc-eb373f dynamic 1/15
192.168.1.215 5cf3fc-eb373f dynamic 1/15
192.168.1.218 5cf3fc-eb373f dynamic 1/15
192.168.1.213 is a physical ethernet line on the P7
192.168.1.215 is a virtial ethernet line on the P7
192.168.1.218 is a physical ethernet line on the rw-ihmc
The gateway for vlan6 and the vlan6 interface on the core is 192.168.6.1
The gateway for vlan4 and the vlan4 interface on the core is 192.168.1.1.
I have cleared the arp cache on both rw-app2 (vlan 4 server) and the core switch.
I set up port mirroring on the core by running the following commands
conf t
mirror 1 port 1/1
int 1/15
monitor all both mirror 1 no-tag-added
This will cause traffic on port 1/15 (the iSeries vlan 4 interface on the core) to be mirrored to port 1/1. I plugged in
my laptop into port 1/1, started a packet sniff, cleared the arp cache on the core, pinged 192.168.1.218, and then inspected the
packet sniff.
I found that the vlan 4 NIC of the iSeries was replying to the "who has" ARP requests for both 192.168.1.213 and 192.168.1.218, even though it only has
192.168.1.213 on it!
I then took the HMC offline (unplugged it from the core)
cleared the ARP cache on the core switch,
tried to ping 192.168.1.218 from the core,
ran a show arp on the core,
Same results as before, the ARP cache on the core shows both 192.168.1.213 and 192.168.1.218 as having the same MAC address, and being plugged into port 1/15
Then I changed the IP address of the HMC to 192.168.1.214
cleared the ARP cache on the core switch
pinged 192.168.1.214 from the core switch
did a show ARP
and it's showing the exact same thing as initially (with the modified IP address). 192.168.1.213 and 192.168.1.214 in the ARP cache both have the same MAC address and port number 1/15
At this point I'm feeling like there has to be some IBM specific piece of software or configuration I'm missing.
Thanks in advance for any help you can provide me!
Taylor Hammerling
IT Manager | RateWatch [cid:image001.jpg@01CF54C9.F7AC2F10] <
https://www.linkedin.com/company/ratewatch?trk=top_nav_home>
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800.348.1831 x4302 | taylor.hammerling@xxxxxxxxxxxxxx<mailto:taylor.hammerling@xxxxxxxxxxxxxx> | rate-watch.com<
http://www.rate-watch.com/>
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