high latency

[Chris Knipe]

Hi,

I have 4 FreeBSD Servers connected to a Cisco 2950 all doing inter-VLAN
routing. Everything is working right, but one server is getting absurdly
high latency through the VLANs.

problem box:
root@wsmd-core01:/home/cknipe# ping 198.19.0.1
PING 198.19.0.1 (198.19.0.1): 56 data bytes
64 bytes from 198.19.0.1: icmp_seq=0 ttl=64 time=1020.571 ms
64 bytes from 198.19.0.1: icmp_seq=2 ttl=64 time=1114.468 ms
64 bytes from 198.19.0.1: icmp_seq=3 ttl=64 time=934.580 ms
64 bytes from 198.19.0.1: icmp_seq=4 ttl=64 time=814.296 ms
64 bytes from 198.19.0.1: icmp_seq=5 ttl=64 time=682.657 ms
64 bytes from 198.19.0.1: icmp_seq=6 ttl=64 time=1173.596 ms
64 bytes from 198.19.0.1: icmp_seq=7 ttl=64 time=1212.085 ms
64 bytes from 198.19.0.1: icmp_seq=8 ttl=64 time=1021.996 ms
64 bytes from 198.19.0.1: icmp_seq=9 ttl=64 time=826.783 ms
64 bytes from 198.19.0.1: icmp_seq=10 ttl=64 time=372.565 ms
^C
--- 198.19.0.1 ping statistics ---
12 packets transmitted, 10 packets received, 16% packet loss
round-trip min/avg/max/stddev = 372.565/917.360/1212.085/241.657 ms


second box:
root@efanious:~# ping 198.19.0.1
PING 198.19.0.1 (198.19.0.1): 56 data bytes
64 bytes from 198.19.0.1: icmp_seq=0 ttl=64 time=1.847 ms
64 bytes from 198.19.0.1: icmp_seq=1 ttl=64 time=1.484 ms
64 bytes from 198.19.0.1: icmp_seq=2 ttl=64 time=1.478 ms
64 bytes from 198.19.0.1: icmp_seq=3 ttl=64 time=1.564 ms
64 bytes from 198.19.0.1: icmp_seq=4 ttl=64 time=1.913 ms
64 bytes from 198.19.0.1: icmp_seq=5 ttl=64 time=3.057 ms
64 bytes from 198.19.0.1: icmp_seq=6 ttl=64 time=1.839 ms
64 bytes from 198.19.0.1: icmp_seq=7 ttl=64 time=1.526 ms
64 bytes from 198.19.0.1: icmp_seq=8 ttl=64 time=2.791 ms
64 bytes from 198.19.0.1: icmp_seq=9 ttl=64 time=1.522 ms
^C
--- 198.19.0.1 ping statistics ---
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max/stddev = 1.478/1.902/3.057/0.537 ms


The other's ping basically the same (1.4ms -> 4ms).


Now, the problematic box is running a RealTek card, netstat -bin reports no
input / output errors. The interface on the Cisco 2950 also doesn't report
any problems or errors on the interface. Does anyone have some
recommendations? I'm thinking of just switching the NIC out, but I'd rather
want to make sure first that is actually the problem.

--
Chris.

[Peter Risdon]

On Mon, 2005-02-21 at 11:52 +0200, Chris Knipe wrote:

> Hi,
>
> I have 4 FreeBSD Servers connected to a Cisco 2950 all doing inter-VLAN
> routing. Everything is working right, but one server is getting absurdly
> high latency through the VLANs.

[...]

> Now, the problematic box is running a RealTek card,

Ugh. You don't say which one, but I just cured a prob with nfs by
replacing a brand new Realtek card with an old digital NIC that was
lying around. Not for the first time, I vow never to use Realtek cards
again.

Peter.

[Chris Knipe]

>> Hi,

>>
>> I have 4 FreeBSD Servers connected to a Cisco 2950 all doing inter-VLAN
>> routing. Everything is working right, but one server is getting absurdly
>> high latency through the VLANs.

>
> [...]
>

>> Now, the problematic box is running a RealTek card,

>
> Ugh. You don't say which one, but I just cured a prob with nfs by
> replacing a brand new Realtek card with an old digital NIC that was
> lying around. Not for the first time, I vow never to use Realtek cards
> again.

Yup. Switched the card and problem solved. I use RealTek mainly because I
have heard that they have the best support for VLANs with large packets
inside those VLANs.

Oh well, we'll be running only cisco on the networking side pretty soon,
then there wont be a use for VLANs on the servers :)

Thanks

--
chris.

[Ted Mittelstaedt]

> -----Original Message-----
> From: [email]owner-freebsd-questions@freebsd.org[/email]
> [mailto:owner-freebsd-questions@freebsd.org]On Behalf Of Peter Risdon
> Sent: Monday, February 21, 2005 3:31 AM
> To: Chris Knipe
> Cc: [email]freebsd-questions@freebsd.org[/email]
> Subject: Re: high latency
>
>
> On Mon, 2005-02-21 at 11:52 +0200, Chris Knipe wrote:

> > Hi,
> >
> > I have 4 FreeBSD Servers connected to a Cisco 2950 all doing

> inter-VLAN

> > routing. Everything is working right, but one server is

> getting absurdly

> > high latency through the VLANs.

>
> [...]
>

> > Now, the problematic box is running a RealTek card,

>
> Ugh. You don't say which one, but I just cured a prob with nfs by
> replacing a brand new Realtek card with an old digital NIC that was
> lying around. Not for the first time, I vow never to use Realtek cards
> again.
>

Realteks seem to have a problem detecting and setting up for the correct
speed/duplex. (The 10/100 versions, that is) If you leave them in AUTO
negotiation mode they only work right if connected to a 10/100 switch.
Otherwise if you have problems they work fine if you hard code the
speed/duplex in the /etc/rc.conf file.

Ted

[Peter Risdon]

On Mon, 2005-02-21 at 03:48 -0800, Ted Mittelstaedt wrote:

> >
> > On Mon, 2005-02-21 at 11:52 +0200, Chris Knipe wrote:

> > > Hi,
> > >
> > > I have 4 FreeBSD Servers connected to a Cisco 2950 all doing

> > inter-VLAN

> > > routing. Everything is working right, but one server is

> > getting absurdly

> > > high latency through the VLANs.

> >
> > [...]
> >

> > > Now, the problematic box is running a RealTek card,

> >
> > Ugh. You don't say which one, but I just cured a prob with nfs by
> > replacing a brand new Realtek card with an old digital NIC that was
> > lying around. Not for the first time, I vow never to use Realtek cards
> > again.
> >

>
> Realteks seem to have a problem detecting and setting up for the correct
> speed/duplex. (The 10/100 versions, that is) If you leave them in AUTO
> negotiation mode they only work right if connected to a 10/100 switch.
> Otherwise if you have problems they work fine if you hard code the
> speed/duplex in the /etc/rc.conf file.

I still feel an aversion to the rl cards, but thanks very much for the
tip.

Peter.

[Skylar Thompson]

Peter Risdon wrote:

>On Mon, 2005-02-21 at 11:52 +0200, Chris Knipe wrote:
>
>

>>Hi,
>>
>>I have 4 FreeBSD Servers connected to a Cisco 2950 all doing inter-VLAN
>>routing. Everything is working right, but one server is getting absurdly
>>high latency through the VLANs.
>>
>>

>
>[...]
>
>
>

>>Now, the problematic box is running a RealTek card,
>>
>>

>
>Ugh. You don't say which one, but I just cured a prob with nfs by
>replacing a brand new Realtek card with an old digital NIC that was
>lying around. Not for the first time, I vow never to use Realtek cards
>again.
>
>

Not for naught is this comment in the source for the FreeBSD driver:

The RealTek 8139 PCI NIC redefines the meaning of 'low end.'

I've had nothing but bad luck from them.

--
-- Skylar Thompson (skylar@cs.earlham.edu)
-- [url]http://www.cs.earlham.edu/~skylar/[/url]


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