I'm experiencing performance issues with linux packet forwarding. I use an old laptop as a router, with iptables to handle masquerading and ipv4 forwarding turned on.
- Intranet network is connected to the gigabit built-in NIC
- Internet network cis onnected to a 32bit PCMCIA card
Measured speeds :
- Internet <-> Router : 11.2 MB/s
- Intranet <-> Router : 112 MB/s
- Intranet <-> Internet : no more than 100 KB/s
I can have both interfaces downloading / uploading at the same time without any issue.
Router hardware configuration :
- Pentium M 1.6GHz
- 1.2 GB RAM
- DELL Latitude D410
Software configuration :
- Linux 2.6.32-5-686 #1 SMP Tue Mar 8 21:36:00 UTC 2011 i686 GNU/Linux (Debian 6)
- iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
- /proc/sys/net/ipv4/ip_forward set to 1
I have no clue why this is happening, does anyone have an idea of where this performance drop could come from ?
I will try reinstalling the operating system, but I do not think it will change anything.