On Sat, Feb 11, 2012 at 12:43 PM, Insan Praja SW <insan.pr...@gmail.com>
wrote:
> Hi Misc@,
>
> Could someone elaborate me with this tcpdump I had? After nat-ing, checksum
> error shows, on the same packet..
>
> rule 173.home.8/(match) [uid 0, pid 9731] pass in on vlan516:
> 172.16.33.254.64264 > 188.255.110.14.51413: S [tcp sum ok]
> 260322197:260322197(0) win 8192 <mss 1436,nop,nop,sackOK> [tos 0x28] (ttl
> 126, id 5689, len 48)
> rule 173.home.13/(match) [uid 0, pid 9731] pass out on vlan500: [orig src
> 172.16.33.254:64264, dst 188.255.110.14:51413] 202.90.195.234.59074 >
> 188.255.110.14.51413: S [bad tcp cksum f54!] 260322197:260322197(0) win
8192
> <mss 1436,nop,nop,sackOK> [tos 0x28] (ttl 125, id 5689, len 48, bad cksum
> 2d4b!)
from man tcpdump
IP Checksum Offload
Some network cards support IP checksum offload. Packet headers for such
interfaces erroneously indicate a bad checksum, since the checksum is
not
calculated until after tcpdump sees the packet.
so maybe related to your case
>
> Thanks,
>
> Insan Praja
>
> dmesg:
> OpenBSD 5.1 (GENERIC.MP) #15: Fri Feb 10 01:01:43 WIT 2012
> B B r...@core01.netaplus.net:/usr/src/sys/arch/i386/compile/GENERIC.MP
> RTC BIOS diagnostic error 80<clock_battery>
> cpu0: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz ("GenuineIntel" 686-class) 2.40
> GHz
> cpu0:
>
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS
H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX,
EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF
> real mem B = 2135588864 (2036MB)
> avail mem = 2090528768 (1993MB)
> mainbus0 at root
> bios0 at mainbus0: AT/286+ BIOS, date 07/23/10, BIOS32 rev. 0 @ 0xfd7e1,
> SMBIOS rev. 2.5 @ 0x7f6b9000 (55 entries)
> bios0: vendor IBM Corp. version "-[GYE144AUS-1.09]-" date 12/16/2010
> bios0: IBM 81Y6793
> acpi0 at bios0: rev 2
> acpi0: sleep states S0 S1 S5
> acpi0: tables DSDT FACP TCPA APIC MCFG SLIC HPET SSDT SSDT ERST DMAR
> acpi0: wakeup devices PCIB(S4) POP3(S4) POP1(S4) POP6(S4) POP5(S4) PEX1(S4)
> PEX2(S4) PEX3(S4) PEX4(S4) PEX5(S4) EHI1(S3) EHI2(S3) PWRB(S3)
> acpitimer0 at acpi0: 3579545 Hz, 24 bits
> acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
> cpu0 at mainbus0: apid 0 (boot processor)
> cpu0: apic clock running at 132MHz
> cpu1 at mainbus0: apid 2 (application processor)
> cpu1: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz ("GenuineIntel" 686-class) 2.40
> GHz
> cpu1:
>
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS
H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX,
EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF
> cpu2 at mainbus0: apid 4 (application processor)
> cpu2: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz ("GenuineIntel" 686-class) 2.40
> GHz
> cpu2:
>
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS
H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX,
EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF
> cpu3 at mainbus0: apid 6 (application processor)
> cpu3: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz ("GenuineIntel" 686-class) 2.40
> GHz
> cpu3:
>
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS
H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX,
EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF
> ioapic0 at mainbus0: apid 8 pa 0xfec00000, version 20, 24 pins
> acpimcfg0 at acpi0 addr 0x80000000, bus 0-255
> acpihpet0 at acpi0: 14318179 Hz
> acpiprt0 at acpi0: bus 0 (PCI0)
> acpiprt1 at acpi0: bus 36 (PCIB)
> acpiprt2 at acpi0: bus 26 (POP3)
> acpiprt3 at acpi0: bus -1 (POP1)
> acpiprt4 at acpi0: bus -1 (POP6)
> acpiprt5 at acpi0: bus 31 (POP5)
> acpiprt6 at acpi0: bus 1 (PEX1)
> acpiprt7 at acpi0: bus 6 (PEX2)
> acpiprt8 at acpi0: bus 11 (PEX3)
> acpiprt9 at acpi0: bus 16 (PEX4)
> acpiprt10 at acpi0: bus 21 (PEX5)
> acpicpu0 at acpi0: PSS
> acpicpu1 at acpi0: PSS
> acpicpu2 at acpi0: PSS
> acpicpu3 at acpi0: PSS
> acpibtn0 at acpi0: PWRB
> bios0: ROM list: 0xc0000/0x8000 0xc8000/0x1000 0xc9000/0x1000
0xca000/0x1000
> ipmi at mainbus0 not configured
> cpu0: Enhanced SpeedStep 2394 MHz: speeds: 2394, 2261, 2128, 1995, 1862,
> 1729, 1596, 1463, 1330, 1197 MHz
> pci0 at mainbus0 bus 0: configuration mode 1 (bios)
> pchb0 at pci0 dev 0 function 0 "Intel Core DMI" rev 0x11
> ppb0 at pci0 dev 3 function 0 "Intel Core PCIE" rev 0x11: apic 8 int 16
> pci1 at ppb0 bus 26
> ppb1 at pci0 dev 5 function 0 "Intel Core PCIE" rev 0x11: apic 8 int 16
> pci2 at ppb1 bus 31
> em0 at pci2 dev 0 function 0 "Intel I340-T2 (82580)" rev 0x01: msi, address
> 00:1b:21:90:00:d0
> em1 at pci2 dev 0 function 1 "Intel I340-T2 (82580)" rev 0x01: msi, address
> 00:1b:21:90:00:d1
> "Intel Core Management" rev 0x11 at pci0 dev 8 function 0 not configured
> "Intel Core Scratch" rev 0x11 at pci0 dev 8 function 1 not configured
> "Intel Core Control" rev 0x11 at pci0 dev 8 function 2 not configured
> "Intel Core Misc" rev 0x11 at pci0 dev 8 function 3 not configured
> "Intel Core QPI Link" rev 0x11 at pci0 dev 16 function 0 not configured
> "Intel Core QPI Routing" rev 0x11 at pci0 dev 16 function 1 not configured
> ehci0 at pci0 dev 26 function 0 "Intel 3400 USB" rev 0x05: apic 8 int 19
> usb0 at ehci0: USB revision 2.0
> uhub0 at usb0 "Intel EHCI root hub" rev 2.00/1.00 addr 1
> ppb2 at pci0 dev 28 function 0 "Intel 3400 PCIE" rev 0x05: apic 8 int 17
> pci3 at ppb2 bus 1
> ppb3 at pci0 dev 28 function 4 "Intel 3400 PCIE" rev 0x05: apic 8 int 17
> pci4 at ppb3 bus 6
> ppb4 at pci4 dev 0 function 0 unknown vendor 0x101b product 0x0452 rev 0x01
> pci5 at ppb4 bus 7
> vga1 at pci5 dev 0 function 0 vendor "Matrox", unknown product 0x0530 rev
> 0x00
> wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation)
> wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
> ppb5 at pci0 dev 28 function 5 "Intel 3400 PCIE" rev 0x05: apic 8 int 16
> pci6 at ppb5 bus 11
> em2 at pci6 dev 0 function 0 "Intel PRO/1000 MT (82574L)" rev 0x00: msi,
> address 00:21:5e:6b:b7:42
> ppb6 at pci0 dev 28 function 6 "Intel 3400 PCIE" rev 0x05: apic 8 int 18
> pci7 at ppb6 bus 16
> ppb7 at pci0 dev 28 function 7 "Intel 3400 PCIE" rev 0x05: apic 8 int 19
> pci8 at ppb7 bus 21
> em3 at pci8 dev 0 function 0 "Intel PRO/1000 MT (82574L)" rev 0x00: msi,
> address 00:21:5e:6b:b7:43
> ehci1 at pci0 dev 29 function 0 "Intel 3400 USB" rev 0x05: apic 8 int 19
> usb1 at ehci1: USB revision 2.0
> uhub1 at usb1 "Intel EHCI root hub" rev 2.00/1.00 addr 1
> ppb8 at pci0 dev 30 function 0 "Intel 82801BA Hub-to-PCI" rev 0xa5
> pci9 at ppb8 bus 36
> pcib0 at pci0 dev 31 function 0 "Intel 3420 LPC" rev 0x05
> pciide0 at pci0 dev 31 function 2 "Intel 3400 SATA" rev 0x05: DMA, channel
0
> configured to native-PCI, channel 1 configured to native-PCI
> pciide0: using apic 8 int 19 for native-PCI interrupt
> wd0 at pciide0 channel 0 drive 0: <WD2502ABYS-23B7A0 39M4511 42C0463IBM>
> wd0: 16-sector PIO, LBA48, 238475MB, 488397168 sectors
> wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 6
> ichiic0 at pci0 dev 31 function 3 "Intel 3400 SMBus" rev 0x05: apic 8 int
18
> iic0 at ichiic0
> sdtemp0 at iic0 addr 0x18: stts424e02
> sdtemp1 at iic0 addr 0x1a: stts424e02
> spdmem0 at iic0 addr 0x50: 2GB DDR3 SDRAM registered ECC PC3-10600 with
> thermal sensor
> spdmem1 at iic0 addr 0x52: 2GB DDR3 SDRAM registered ECC PC3-10600 with
> thermal sensor
> pciide1 at pci0 dev 31 function 5 "Intel 3400 SATA" rev 0x05: DMA, channel
0
> wired to native-PCI, channel 1 wired to native-PCI
> pciide1: using apic 8 int 18 for native-PCI interrupt
> isa0 at pcib0
> isadma0 at isa0
> com0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo
> com1 at isa0 port 0x2f8/8 irq 3: ns16550a, 16 byte fifo
> 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
> spkr0 at pcppi0
> npx0 at isa0 port 0xf0/16: reported by CPUID; using exception 16
> mtrr: Pentium Pro MTRR support
> uhub2 at uhub0 port 1 "Intel Rate Matching Hub" rev 2.00/0.00 addr 2
> cdce0 at uhub2 port 3 configuration 1 interface 0 "IBM RNDIS/CDC ETHER" rev
> 2.00/2.15 addr 3
> cdce0: address 02:21:5e:6b:b7:45
> uhub3 at uhub1 port 1 "Intel Rate Matching Hub" rev 2.00/0.00 addr 2
> vscsi0 at root
> scsibus0 at vscsi0: 256 targets
> softraid0 at root
> scsibus1 at softraid0: 256 targets
> root on wd0a (9a9bfafa230e2a25.a) swap on wd0b dump on wd0b
>
>
>
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