Unresponsive bridge during active ssh connection

[Diyan Christian <sauron@lug.stikom.edu>]

Hi, good day,

I've succesfully setup an OpenBSD 2.9 bridge (ipfilter), 
and assign IP address on one of the interface (internal network). 
During my active ssh session, the box sometimes seems so slow 
in responding to my active session.
Is there any tunable kernel parameters I can tweak to gain this box best 
performances?
(besides changing the hardware of course) 
I'm compiling a new kernel, after the GENERIC kernel gets panicked several 
times, and
the system is stable ever since without the need to reboot, 
I'm also increased NMBCLUSTER=2048, after reading the FAQ,
or is it normal considering the network loads, that this box has to handle
the active sessions? (vmstat output said that the cpu is mostly 99% idle even 
in
the peak hours where the active session is about 2600).

I was also aware that the box hardware is an ancient one, but I believe
this box can handle the loads (for the moment at least).
Any advice in tuning for performance is very welcomed.

Thank you in advance.

dmesg from the GENERIC kernel below:
OpenBSD 2.9 (GENERIC) #653: Sat Apr 28 13:57:59 MDT 2001
    deraadt@i386.openbsd.org:/usr/src/sys/arch/i386/compile/GENERIC
cpu0: F00F bug workaround installed
cpu0: Intel Pentium (P54C) ("GenuineIntel" 586-class) 150 MHz
cpu0: FPU,V86,DE,PSE,TSC,MSR,MCE,CX8
real mem  = 33140736 (32364K)
avail mem = 25804800 (25200K)
using 430 buffers containing 1761280 bytes (1720K) of memory
mainbus0 (root)
bios0 at mainbus0: AT/286+(29) BIOS, date 06/05/97, BIOS32 rev. 0 @ 0xfaea0
apm0 at bios0: Power Management spec V1.2
apm0: AC on, battery charge unknown
pcibios0 at bios0: rev. 2.1 @ 0xf0000/0xb34c
pcibios0: PCI BIOS has 5 Interrupt Routing table entries
pcibios0: PCI bus #0 is the last bus
bios0: ROM list: 0xc0000/0x8000 0xc8000/0x800 0xc9000/0x800 0xca000/0x7000
pci0 at mainbus0 bus 0: configuration mode 1 (bios)
pchb0 at pci0 dev 0 function 0 "Intel 82437VX" rev 0x02
pcib0 at pci0 dev 7 function 0 "Intel 82371SB PCI-ISA" rev 0x01
pciide0 at pci0 dev 7 function 1 "Intel 82371SB IDE" rev 0x00: DMA, channel 0 
wired to compatibility, channel 1 wired to compatibility
xl0 at pci0 dev 17 function 0 "3Com 3c905C 100Base-TX" rev 0x74: irq 11 
address 00:01:02:96:fd:12 
exphy0 at xl0 phy 24: Broadcom 3C905C internal PHY, rev. 6
xl1 at pci0 dev 18 function 0 "3Com 3c905C 100Base-TX" rev 0x74: irq 10 
address 00:01:02:96:f9:b6
exphy1 at xl1 phy 24: Broadcom 3C905C internal PHY, rev. 6
ahc1 at pci0 dev 19 function 0 "Adaptec AHA-2940U" rev 0x00: irq 9
ahc1: Single Channel A, SCSI Id=7, 16/255 SCBs
scsibus0 at ahc1: 8 targets
ahc1: target 0 synchronous at 20.0MHz, offset = 0xf
sd0 at scsibus0 targ 0 lun 0: <IBM, DCAS-32160W, S65A> SCSI2 0/direct fixed
sd0: 2063MB, 8188 cyl, 3 head, 172 sec, 512 bytes/sec, 4226725 sec total
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
vga0 at isa0 port 0x3b0/48 iomem 0xa0000/131072
wsdisplay0 at vga0: console (80x25, vt100 emulation), using wskbd0
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
pcppi0 at isa0 port 0x61
midi0 at pcppi0: <PC speaker>
sysbeep0 at pcppi0
lpt0 at isa0 port 0x378/4 irq 7
npx0 at isa0 port 0xf0/16: using exception 16
pccom0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo
pccom1 at isa0 port 0x2f8/8 irq 3: 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 240 netmask e40 ttymask ec2
pctr: 586-class performance counters and user-level cycle counter enabled
dkcsum: sd0 matched BIOS disk 80
root on sd0a
rootdev=0x400 rrootdev=0xd00 rawdev=0xd02


Warmest regards from Indonesia,
-- 
Diyan Christian
oblek@lug.stikom.edu