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I have an interesting situation on my network right now. I have a 10.1.1.x space that I have a few dozen static IPs on (servers, etc.) and a 10.1.4.x space where we have other machines (DHCP-fed user machines). Some network slowness has been reported by some of my users and I'm finding that it's partly manifested in the following example.

I have a 10.1.1.x VMWare host server (one physical NIC) which has a 10.1.4.x VM running on it. If I ping the host from my workstation (also 10.1.4.x), some responses time-out:

C:\>ping 10.1.1.44

Pinging 10.1.1.44 with 32 bytes of data:
Request timed out.
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Request timed out.
Request timed out.
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Request timed out.
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Request timed out.
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Request timed out.
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Reply from 10.1.1.44: bytes=32 time<1ms TTL=127
Request timed out.
Request timed out.

However, pinging the guest has no such trouble:

C:\>ping 10.1.4.126

Pinging 10.1.4.126 with 32 bytes of data:
Reply from 10.1.4.126: bytes=32 time=3ms TTL=128
Reply from 10.1.4.126: bytes=32 time<1ms TTL=128
Reply from 10.1.4.126: bytes=32 time=10ms TTL=128
Reply from 10.1.4.126: bytes=32 time=9ms TTL=128
Reply from 10.1.4.126: bytes=32 time=9ms TTL=128
Reply from 10.1.4.126: bytes=32 time=11ms TTL=128
Reply from 10.1.4.126: bytes=32 time=3ms TTL=128
Reply from 10.1.4.126: bytes=32 time=4ms TTL=128
Reply from 10.1.4.126: bytes=32 time=9ms TTL=128
Reply from 10.1.4.126: bytes=32 time=7ms TTL=128
Reply from 10.1.4.126: bytes=32 time=1ms TTL=128
Reply from 10.1.4.126: bytes=32 time=6ms TTL=128
Reply from 10.1.4.126: bytes=32 time=7ms TTL=128
Reply from 10.1.4.126: bytes=32 time=4ms TTL=128
Reply from 10.1.4.126: bytes=32 time=8ms TTL=128
Reply from 10.1.4.126: bytes=32 time=3ms TTL=128
Reply from 10.1.4.126: bytes=32 time=1ms TTL=128
Reply from 10.1.4.126: bytes=32 time=8ms TTL=128
Reply from 10.1.4.126: bytes=32 time=4ms TTL=128
Reply from 10.1.4.126: bytes=32 time=9ms TTL=128
Reply from 10.1.4.126: bytes=32 time=8ms TTL=128
Reply from 10.1.4.126: bytes=32 time=1ms TTL=128
Reply from 10.1.4.126: bytes=32 time=10ms TTL=128
Reply from 10.1.4.126: bytes=32 time=4ms TTL=128

How could this be?

Any direction is much appreciated.

share|improve this question
2  
That's extremely high latency to ping a guest from the host. That should be <1 ms. You have something missconfigured, and it's very hard to tell what. Could you additionally post a ipconfig /all for host & VM and a tracert 10.1.4.126 / tracert 10.1.1.44 from the host? Additionally, ping 10.1.4.126 -t does a "continous ping", no need to re-start the command. –  MichelZ Jul 19 '12 at 15:36
    
Both pings are from my local workstation (a different machine) on 10.1.4.x. I'll try to get that info. –  Tim Lehner Jul 19 '12 at 15:53
1  
Need more info about the host. Version of ESX 4.x, ESXi 5? You say you have a single NIC, but then suggest the host network and the VM network are on different subnets. Ideally, the next step would be mirror the switch port (Cisco -> read SPAN port), and see what's actually happening with the ICMP traffic. Is the host receiving it, for example. Have you tried SSH'ing to the host and pinging outbond? –  Simon Catlin Jul 28 '12 at 22:00
1  
I had a similar problem that was resolved by deleting and adding back the virtual nic adapter on the vm –  user166013 Mar 22 '13 at 17:13

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