# FreeBSD network slowness



## suguprathap (Feb 11, 2015)

Hi,

I have a situation, we have two different networks 178.38.0.0 and 179.30.0.0 connected through VPN. If we transfer a file from 172.38.0.0 network machine (either FreeBSD or Red Hat) to 172.30.0.0 network machine(FreeBSD) the transfer rate is very slow, its like kbps. But if the destination is Red Hat or CentOS the transfer rate is like Mbps, if it is within the same network also then the transfer rate is Mbps. Please help me to solve this.

Frankly speaking: Across the network the transfer rate is Kbps, if the destination is FreeBSD.

```
178.38.0.0                 179.30.0.0                 speed
FreeBSD          to          FreeBSD                   kbps
centos            to          FreeBSD                   kbps
FreeBSD          to           redhat                    mbps
```
Thanks in advance,
Suguprathap


----------



## wblock@ (Feb 11, 2015)

Very slow network speeds always suggest duplex mismatch as the first thing to check.  That could be due to network cards or switches.


----------



## suguprathap (Feb 18, 2015)

The network cards and switches are fine and the slowness is only with FreeBSD to FreeBSD OS and not with other operating system. I suspect some os level configuration need to be checked.


----------



## diizzy (Feb 18, 2015)

I had a very interesting issue where I could download at 100mbit whereas uploading wouldn't go above ~100kbyte/s while this was back in the 4.X days it turned out that my 3com network card was dying. No obvious errors or anything except the very odd upload speed.

In your case if you can get full speed out of the server without going thru the VPN I'd fire up tcpdump/wireshark and compare traffic between a fast host and the FreeBSD box.
//Danne


----------



## junovitch@ (Feb 19, 2015)

If your FreeBSD machine in 172.38 can talk full speed to the Red Hat machine in 172.30, it seems like there is something unique with the FreeBSD machine in 172.30.  Check for errors with `netstat -i` and `netstat -s | egrep 'bad|checksum'`. Look for signs of link flapping that could be caused by duplex issues.  `sysctl -a | grep link_irq`.


----------

