Dear all, My os: Redhat 9 with 2.4.20 shipped kernel with redhat. I have even changed my hardware and tried but same error. I have changed the kernel to 2.4.21 then also i m getting this error. when i am starting my bandwidth script i m getting below errors. then my machine gets unusable. This is surely something related with tc /iptables and kernel but i cant sort out what is the problem. Can any body over have experience such problem. ???????????????? Starting Bandwidth Management: ip_conntrack (4031 buckets, 32248 max) Kernel BUG at slab.c:1130 invalid operand: 0000 CPU: 0 EIP: 0010:[<c012e188>] Not tainted EFLAGS: 00010202 eax: 000001f0 ebx: 00000000 ecx: c15732d0 edx: c02194bc esi: c15732c0 edi: 000001f0 ebp: c15732c0 esp: dc1c3ae0 ds: 0018 es: 0018 ss: 0018 Process tc (pid: 1164, stackpage=dc1c3000) Stack: 000001f0 00000000 c1573480 000001f0 c15732c0 c012e20a c15732c0 c15732c0 00000246 000001f0 c15732c0 c012e4fd c15732c0 000001f0 000001d2 c1573480 00000246 000001f0 dc137000 c02209c0 dc137184 df496c00 c01af3f3 00000064 Call Trace: [<c012e20a>] [<c012e4fd>] [<c01af3f3>] [<e017f102>] [<c01b0e4b>] " " " Code: 0f 0b 6a 04 bb b6 1f c0 89 7c 24 04 b8 03 00 00 00 81 64 24 <0>Kernel panice: Aiee, killing interrupt handler! In interrupt handler - not sycning Any ideas, -- Joel N.Solanki Network Administrator Phone No: 0265-550001/2/3/4/5 Ext: 211/212 Digtial 2 Virtual Internet Service Provider. http://www.packetraptor.com/ http://www.d2visp.com/ Gujarat (India)