I recently got Fusion service with a Comtrend NexusLink 5631 and 8 Static IP addresses assigned to me. Since I have more than 8 devices on my network, I would like to assign 7 of the IP addresses to machines I access remotely, and use the 8th IP address as a public IP address of a NAT box.
This works fine with an external NAT box, but all else equal I'd rather have fewer devices, so it would be nice if I could use the Comtrend modem as both a bridge and a NAT device.
After fiddling with the settings, I found that I could create *two* WAN interfaces with the same VPI/VCI, so I created one bridge interface, and one MER. The bridge interface let me use my static IP addresses, while the MER interface let me configure NAT and a DHCP server. I'm running Sonic's IP addresses and my own RFC1918 ones on the same Ethernet, which works fine.
The problem I'm running into is that the NATted IP addresses are significantly slower than the public ones--like 18% slower. Using a public IP address, I see download rates of 4.25 MB/sec. With an RFC1918 one, I can only get 3.5 MB/sec.
Is creating two WAN interfaces the right way to do what I want to do, or is there a better way to configure the modem? Does the Comtrend just have a poor NAT implementation, or does this depend on the order in which I define WAN interfaces or something? Can someone give me any suggestions on how to avoid this NAT penalty?
Thanks.
This works fine with an external NAT box, but all else equal I'd rather have fewer devices, so it would be nice if I could use the Comtrend modem as both a bridge and a NAT device.
After fiddling with the settings, I found that I could create *two* WAN interfaces with the same VPI/VCI, so I created one bridge interface, and one MER. The bridge interface let me use my static IP addresses, while the MER interface let me configure NAT and a DHCP server. I'm running Sonic's IP addresses and my own RFC1918 ones on the same Ethernet, which works fine.
The problem I'm running into is that the NATted IP addresses are significantly slower than the public ones--like 18% slower. Using a public IP address, I see download rates of 4.25 MB/sec. With an RFC1918 one, I can only get 3.5 MB/sec.
Is creating two WAN interfaces the right way to do what I want to do, or is there a better way to configure the modem? Does the Comtrend just have a poor NAT implementation, or does this depend on the order in which I define WAN interfaces or something? Can someone give me any suggestions on how to avoid this NAT penalty?
Thanks.