Slow NAT Gentoo 1.4_rc2

cynninge · n00b Joined: 03 Jul 2002 Posts: 31

I setup NAT on my old Dell Inspiron 7000 Laptop with two PCMCIA NIC's from intel etherexpress pro/100 mobile adapter 32-bit Cardbus and the NAT box is networked to my net thru a hub with at present one other connection
Now the problem is that without the NAT in place my desktop usually gets 4.6Mbps to cablevision's speedcheck servers

But turn the NAT on and voila the speed drops down to .5Mbps now that's a whopping drop.
The NAT how-to from TLDP.org seems to say that a 486 with 16 megs of ram can easily handle 1.5Mbps connections

this laptop is a frigging P2 300Mhz and 384Megs of ram dedicated system that may eventually run a web in addition to being a NAT box.

Any idea which ethernet driver module i oughta compile into the kernel? i used the etherexpress driver and i selected all the drivers under pcmcia i figure one oughta stick.

Any idea where the bottleneck is guys?

I don't want to go purchase a router from linksys if i dont have to :-D

herring · Apprentice Joined: 22 Jul 2002 Posts: 187 Location: Norway

cynninge · n00b Joined: 03 Jul 2002 Posts: 31

i tried changing the drivers and recompiling the kernel... maybe cardbus adapters cant handle that kind of bandwidth?

cynninge · n00b Joined: 03 Jul 2002 Posts: 31

i tried changing the drivers and recompiling the kernel... maybe cardbus adapters cant handle that kind of bandwidth?

cynninge · n00b Joined: 03 Jul 2002 Posts: 31

does anyone know a way to figure out how much traffic i can push through each one of the cards? I need to figure out why my PC 100 cards are delivering nowhere near 100Mbps sec and only a measly .5 Mbps

my network is connected as follows.
cable modem--->Latptop eth0--->NAT--->Laptop eth1--->
HUB uplink port-->Port 1->Desktop1
-->Port 2->Desktop2(off while testing NAT)
-->Port 3->Desktop3(off while testing NAT)
-->Port 4->WLAN bridge(off while testing NAT)

cynninge · n00b Joined: 03 Jul 2002 Posts: 31

no tx/rx errors sorry i had a discrete math exam and some programming assignments to do between didnt get a chance to reply to your message

cynninge · n00b Joined: 03 Jul 2002 Posts: 31

ok here's some new info.. i borrowed a friend's router and set it up and i get 5 mbps directly into the laptop wow! how is a 75 mhz strong arm beating my p2 ?

well after checking the config on the router it says the connection between the router and the 3 com modem registers are 10 Mbps/half duplex what mode? i can't tell
3 com home connect cable modem for optimum online in NY

and mii-diag with the router shows that the cards negotiate with the router and chose 100baseTx-FD media type

now when i plug the same cards into the cable box
mii-diag cant figure out what speed the card is in or what media it is using. although we do get some really slow network connections. The cable box apparently is not autonegotiating with the card and this is causing the card to go wonkers

I tried using mii-diag -F 10baseT-HD for half duplex like i saw in the router screen but this doesnt help...
I'm out of ideas... the difference is that my desktop cards dont seem to have this problem although the pcmcia nics do.

Any solutions guys? a little help here...

cynninge · n00b Joined: 03 Jul 2002 Posts: 31

dont rush in with the replies!!
i have a tulip_cb and cb_enabler listed as modules
how do i go about setting it to use 10baseT half duplex?
ifconfig eth0 media 10baseT doesnt work
i tried adding the following lines to /etc/modules.d/aliases

cynninge · n00b Joined: 03 Jul 2002 Posts: 31

Just putting a heartbeat on this post so that it doesnt get buried and unanswered in the list of other posts. I really need help with this. I am at my wits end. I am not going to give up to this stupid machine after putting in so much time on it.