Having trouble setting up a PPPoE connection...

[da kalto <da_(_dot_)_kalto_(_at_)_gmail_(_dot_)_com>]

Hi everyone,
I've been using OpenBSD as a PPPoE NAT/firewall from 3.1 to 3.4 and i
never had any
trouble.

I recently decided to (re-)install an OpenBSD 3.6 as a NAT/firewall
and i'm having trouble
with its PPPoE connection. I'm using exactly the same ppp.conf i used
with my last 3.4
setup, which worked fine.

As you'll see in the following dmesg the box has 3 NICs, an Intel
82557, a 3Com 3c905B
and a 3Com 3c900. They all seems to work fine, it connects to the
internet using xl0 or xl1
and everything works fine for some time, but after 15 minutes the
connection seems to
drop. If I let the ping goes after another 2 or 3 minutes it starts
giving "ping: sendto: No
buffer space available". The only error log I get from syslog is:

Feb  8 17:05:10 afnu ppp[17871]: Warning: 0.0.0.0/0: Change route
failed: errno: No such
process
Feb  8 17:05:10 afnu ppp[17871]: Warning: ff02::%tun0/32: Change route
failed: errno:
Undefined error: 0

If i kill -HUP the ppp process and restart it... it re-connects for
another 15 minutes before
dropping again... 

Could it be the NICs? xl1 and fxp0 are using the same IRQ which isn't
the best thing i
heard... Anyone can suggest me some good NICs?

Well, any hint would be really appreciated.

----- start of dmesg -----
OpenBSD 3.6 (GENERIC) #59: Fri Sep 17 12:32:57 MDT 2004
    deraadt_(_at_)_i386_(_dot_)_openbsd_(_dot_)_org:/usr/src/sys/arch/i386/compile/GENERIC
cpu0: Intel Pentium Pro ("GenuineIntel" 686-class, 256KB L2 cache) 199 MHz
cpu0: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV
real mem  = 133799936 (130664K)
avail mem = 115474432 (112768K)
using 1658 buffers containing 6791168 bytes (6632K) of memory
mainbus0 (root)
bios0 at mainbus0: AT/286+(54) BIOS, date 02/12/97, BIOS32 rev. 0 @ 0xf7aa0
pcibios0 at bios0: rev 2.1 @ 0xf0000/0x67c
pcibios0: PCI BIOS has 5 Interrupt Routing table entries
pcibios0: PCI Interrupt Router at 000:01:0 ("Intel 82371SB ISA" rev 0x00)
pcibios0: PCI bus #0 is the last bus
bios0: ROM list: 0xc0000/0x8000 0xc8000/0x800
cpu0 at mainbus0
pci0 at mainbus0 bus 0: configuration mode 1 (bios)
pchb0 at pci0 dev 0 function 0 "Intel 82441FX" rev 0x02
pcib0 at pci0 dev 1 function 0 "Intel 82371SB ISA" rev 0x01
pciide0 at pci0 dev 1 function 1 "Intel 82371SB IDE" rev 0x00: DMA,
channel 0 wired to
compatibility, channel 1 wired to compatibility
wd0 at pciide0 channel 0 drive 0: <FUJITSU MPD3043AT>
wd0: 16-sector PIO, LBA, 4125MB, 8448300 sectors
wd0(pciide0:0:0): using PIO mode 4, DMA mode 2
pciide0: channel 1 disabled (no drives)
fxp0 at pci0 dev 9 function 0 "Intel 82557" rev 0x05: irq 12, address
00:04:ac:58:ce:0d
inphy0 at fxp0 phy 1: i82555 10/100 media interface, rev. 0
xl0 at pci0 dev 10 function 0 "3Com 3c905B 100Base-TX" rev 0x30: irq
10, address
00:50:da:22:89:09
exphy0 at xl0 phy 24: 3Com internal media interface
vga1 at pci0 dev 12 function 0 "Cirrus Logic CL-GD5434-8" rev 0x26
wsdisplay0 at vga1: console (80x25, vt100 emulation)
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
xl1 at pci0 dev 13 function 0 "3Com 3c900 10Base-T" rev 0x00: irq 12, address 
00:60:97:96:e9:75
isa0 at pcib0
isadma0 at isa0
pckbc0 at isa0 port 0x60/5
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pcppi0 at isa0 port 0x61
midi0 at pcppi0: <PC speaker>
sysbeep0 at pcppi0
npx0 at isa0 port 0xf0/16: using exception 16
pccom0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo
fdc0 at isa0 port 0x3f0/6 irq 6 drq 2
fd0 at fdc0 drive 0: 1.44MB 80 cyl, 2 head, 18 sec
biomask ebed netmask ffed ttymask ffef
pctr: 686-class user-level performance counters enabled
mtrr: Pentium Pro MTRR support
dkcsum: wd0 matched BIOS disk 80
root on wd0a
rootdev=0x0 rrootdev=0x300 rawdev=0x302
----- end of dmesg -----