Linux RH7.3 and CentOS-4 (=RHEL 4) won't connect

We've been battling for a while to get RH 7.3 and/or CentOS 4 (= RHEL 4) to connect to iBurst using Ethernet connection. Windows and Linksys work fine, but not direct from the Linux box. And from Linux, ADSL and MyWireless work fine.

Here's the trace:

PPPoE PADI
PPPoE PADO [AC-Name "00:C0:EE:C3:81:10"]
PPPoE PADR
PPPoE PADS [ses 0x1] [Service-Name]
PPPoE [ses 0x1] LCP 26: Conf-Req(1), MRU=1392, ACCM=00000000, Auth-Prot PAP, Magic-Num=2772262f
PPPoE [ses 0x1] LCP 22: Conf-Req(1), ACCM=00000000, Magic-Num=6c908a56, PFC, ACFC
PPPoE [ses 0x1] LCP 26: Conf-Ack(1), MRU=1392, ACCM=00000000, Auth-Prot PAP, Magic-Num=2772262f
PPPoE [ses 0x1] LCP 22: Conf-Ack(1), ACCM=00000000, Magic-Num=6c908a56, PFC, ACFC
PPPoE [ses 0x1] unknown-0x0001 29:
PPPoE [ses 0x1] unknown-0x0001 29:
PPPoE [ses 0x1] unknown-0x0001 29:
PPPoE [ses 0x1] unknown-0x0001 29:
PPPoE [ses 0x1] unknown-0x0001 29:
PPPoE [ses 0x1] unknown-0x0001 29:
PPPoE [ses 0x1] unknown-0x0001 29:
PPPoE [ses 0x1] unknown-0x0001 29:
PPPoE [ses 0x1] unknown-0x0001 29:
PPPoE [ses 0x1] unknown-0x0001 29:
PPPoE [ses 0x1] LCP 46: Term-Req(2)
PPPoE [ses 0x1] LCP 6: Term-Ack(2)
PPPoE PADT [ses 0x1] [Generic-Error "RP-PPPoE: System call error"]

On a working system, after the Conf-Ack we see a PPP PA Authenticate-Request. For some reason this is not happening here.

At that point in the hex trace we see that we are putting out a 01 (Padding Protocol) instead of c0 23 (Password Authentication Protocol).

But we don't know what is causing this! Any help / suggestions would be appreciated.

Is there a specific reason why you are not using a router/firewall to connect to iBurst? I see a lot of this sort of problem here, with people trying to do direct PPPoE to the UTD from Linux. I havent investigated why it does that but I can tell you using a router will save you a lot of hassles later.

Smoothwall (or IPCop) is able to connect to iBurst, you have to tweak the MTU size manually.

neillr said:

...
PPPoE PADS [ses 0x1] [Service-Name]
PPPoE [ses 0x1] LCP 26: Conf-Req(1), MRU=1392, ACCM=00000000, Auth-Prot PAP, Magic-Num=2772262f
PPPoE [ses 0x1] LCP 22: Conf-Req(1), ACCM=00000000, Magic-Num=6c908a56, PFC, ACFC
PPPoE [ses 0x1] LCP 26: Conf-Ack(1), MRU=1392, ACCM=00000000, Auth-Prot PAP, Magic-Num=2772262f...

Click to expand...

MRU=MTU? Maybe set it to 1352.

Problem solved

The_Unbeliever - thanks for the tip. We checked out a Smoothwall config and saw that we were missing the default-asyncmap parameter in our pppd config.

We don't know why this did the trick - this is what the pppd man page says about this parameter:

default-asyncmap
Disable asyncmap negotiation, forcing all control characters to be escaped for both the transmit and the receive direction.