I have a machine that has been serving as NAT gateway and VPN server (both pptp/poptop and openvpn) since 5.0 without problems.
On 5.2 I switched poptop to npppd compiled from sources and was very happy with it. With release of 5.3 I added second machine as CARP failover backup. In last 10 days machine hanged twice. I do not have hang message from the first time, but this time i read this: uvm_fault(0xd8f5f680, 0x0, 0, 3) -> e kernel: page fault trap, code=0 Stopped at pipex_close_session+0xc4: movl %eax,0x6c(%exc) ddb{3}> Below is my dmesg: OpenBSD 5.3 (GENERIC.MP) #58: Tue Mar 12 18:43:53 MDT 2013 dera...@i386.openbsd.org:/usr/src/sys/arch/i386/compile/GENERIC.MP cpu0: Intel(R) Xeon(R) CPU E5420 @ 2.50GHz ("GenuineIntel" 686-class) 2.51 GHz cpu0: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,LONG,SSE3,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,DCA,SSE4.1,LAHF,PERF real mem = 2145267712 (2045MB) avail mem = 2099216384 (2001MB) mainbus0 at root bios0 at mainbus0: AT/286+ BIOS, date 12/31/99, BIOS32 rev. 0 @ 0xf0000, SMBIOS rev. 2.4 @ 0xee000 (68 entries) bios0: vendor HP version "P58" date 07/10/2009 bios0: HP ProLiant DL360 G5 acpi0 at bios0: rev 2 acpi0: sleep states S0 S4 S5 acpi0: tables DSDT FACP SPCR MCFG HPET SPMI ERST APIC FFFF BERT HEST SSDT acpi0: wakeup devices PCI0(S5) acpitimer0 at acpi0: 3579545 Hz, 24 bits acpimcfg0 at acpi0 addr 0xe0000000, bus 0-255 acpihpet0 at acpi0: 14318179 Hz acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat cpu0 at mainbus0: apid 0 (boot processor) cpu0: apic clock running at 333MHz cpu1 at mainbus0: apid 2 (application processor) cpu1: Intel(R) Xeon(R) CPU E5420 @ 2.50GHz ("GenuineIntel" 686-class) 2.51 GHz cpu1: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,LONG,SSE3,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,DCA,SSE4.1,LAHF,PERF cpu2 at mainbus0: apid 1 (application processor) cpu2: Intel(R) Xeon(R) CPU E5420 @ 2.50GHz ("GenuineIntel" 686-class) 2.51 GHz cpu2: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,LONG,SSE3,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,DCA,SSE4.1,LAHF,PERF cpu3 at mainbus0: apid 3 (application processor) cpu3: Intel(R) Xeon(R) CPU E5420 @ 2.50GHz ("GenuineIntel" 686-class) 2.51 GHz cpu3: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,LONG,SSE3,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,DCA,SSE4.1,LAHF,PERF ioapic0 at mainbus0: apid 8 pa 0xfec00000, version 20, 24 pins ioapic1 at mainbus0: apid 9 pa 0xfec80000, version 20, 24 pins acpiprt0 at acpi0: bus 1 (IP2P) acpiprt1 at acpi0: bus 11 (IPE1) acpiprt2 at acpi0: bus 10 (IPE4) acpiprt3 at acpi0: bus 16 (P2P2) acpiprt4 at acpi0: bus 9 (PT02) acpiprt5 at acpi0: bus 6 (PT03) acpiprt6 at acpi0: bus 19 (PT04) acpiprt7 at acpi0: bus 3 (NB01) acpiprt8 at acpi0: bus 5 (NB02) acpiprt9 at acpi0: bus 0 (PCI0) acpicpu0 at acpi0: C3, C1 acpicpu1 at acpi0: C3, C1 acpicpu2 at acpi0: C3, C1 acpicpu3 at acpi0: C3, C1 acpitz0 at acpi0: critical temperature is 31 degC bios0: ROM list: 0xc0000/0xb000 0xcc400/0x4000 0xe6000/0x2000! ipmi at mainbus0 not configured pci0 at mainbus0 bus 0: configuration mode 1 (bios) pchb0 at pci0 dev 0 function 0 "Intel 5000P Host" rev 0xb1 ppb0 at pci0 dev 2 function 0 "Intel 5000 PCIE" rev 0xb1 pci1 at ppb0 bus 9 ppb1 at pci1 dev 0 function 0 "Intel 6321ESB PCIE" rev 0x01 pci2 at ppb1 bus 10 ppb2 at pci2 dev 0 function 0 "Intel 6321ESB PCIE" rev 0x01 pci3 at ppb2 bus 11 ppb3 at pci2 dev 1 function 0 "Intel 6321ESB PCIE" rev 0x01 pci4 at ppb3 bus 14 ppb4 at pci2 dev 2 function 0 "Intel 6321ESB PCIE" rev 0x01 pci5 at ppb4 bus 15 ppb5 at pci1 dev 0 function 3 "Intel 6321ESB PCIE-PCIX" rev 0x01 pci6 at ppb5 bus 16 ppb6 at pci0 dev 3 function 0 "Intel 5000 PCIE" rev 0xb1 pci7 at ppb6 bus 6 ciss0 at pci7 dev 0 function 0 "Hewlett-Packard Smart Array" rev 0x04: apic 8 int 16 ciss0: 1 LD, HW rev 4, FW 7.08/7.08, 64bit fifo scsibus0 at ciss0: 1 targets sd0 at scsibus0 targ 0 lun 0: <HP, LOGICAL VOLUME, 7.08> SCSI3 0/direct fixed sd0: 139979MB, 512 bytes/sector, 286677120 sectors ppb7 at pci0 dev 4 function 0 "Intel 5000 PCIE x8" rev 0xb1 pci8 at ppb7 bus 19 em0 at pci8 dev 0 function 0 "Intel PRO/1000 MT (82574L)" rev 0x00: msi, address 2c:27:d7:15:20:67 ppb8 at pci0 dev 5 function 0 "Intel 5000 PCIE" rev 0xb1 pci9 at ppb8 bus 22 ppb9 at pci0 dev 6 function 0 "Intel 5000 PCIE" rev 0xb1 pci10 at ppb9 bus 2 ppb10 at pci10 dev 0 function 0 "ServerWorks PCIE-PCIX" rev 0xc3 pci11 at ppb10 bus 3 bnx0 at pci11 dev 0 function 0 "Broadcom BCM5708" rev 0x12: apic 8 int 18 ppb11 at pci0 dev 7 function 0 "Intel 5000 PCIE" rev 0xb1 pci12 at ppb11 bus 4 ppb12 at pci12 dev 0 function 0 "ServerWorks PCIE-PCIX" rev 0xc3 pci13 at ppb12 bus 5 bnx1 at pci13 dev 0 function 0 "Broadcom BCM5708" rev 0x12: apic 8 int 19 pchb1 at pci0 dev 16 function 0 "Intel 5000 Error Reporting" rev 0xb1 pchb2 at pci0 dev 16 function 1 "Intel 5000 Error Reporting" rev 0xb1 pchb3 at pci0 dev 16 function 2 "Intel 5000 Error Reporting" rev 0xb1 pchb4 at pci0 dev 17 function 0 "Intel 5000 Reserved" rev 0xb1 pchb5 at pci0 dev 19 function 0 "Intel 5000 Reserved" rev 0xb1 pchb6 at pci0 dev 21 function 0 "Intel 5000 FBD" rev 0xb1 pchb7 at pci0 dev 22 function 0 "Intel 5000 FBD" rev 0xb1 uhci0 at pci0 dev 29 function 0 "Intel 6321ESB USB" rev 0x09: apic 8 int 16 uhci1 at pci0 dev 29 function 1 "Intel 6321ESB USB" rev 0x09: apic 8 int 17 uhci2 at pci0 dev 29 function 2 "Intel 6321ESB USB" rev 0x09: apic 8 int 18 uhci3 at pci0 dev 29 function 3 "Intel 6321ESB USB" rev 0x09: apic 8 int 19 ehci0 at pci0 dev 29 function 7 "Intel 6321ESB USB" rev 0x09: apic 8 int 16 usb0 at ehci0: USB revision 2.0 uhub0 at usb0 "Intel EHCI root hub" rev 2.00/1.00 addr 1 ppb13 at pci0 dev 30 function 0 "Intel 82801BA Hub-to-PCI" rev 0xd9 pci14 at ppb13 bus 1 vga1 at pci14 dev 3 function 0 "ATI ES1000" rev 0x02 wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation) wsdisplay0: screen 1-5 added (80x25, vt100 emulation) radeondrm0 at vga1: apic 8 int 23 drm0 at radeondrm0 "Compaq iLO" rev 0x03 at pci14 dev 4 function 0 not configured "Compaq iLO" rev 0x03 at pci14 dev 4 function 2 not configured uhci4 at pci14 dev 4 function 4 "Hewlett-Packard USB" rev 0x00: apic 8 int 22 "Hewlett-Packard IPMI" rev 0x00 at pci14 dev 4 function 6 not configured usb1 at uhci4: USB revision 1.0 uhub1 at usb1 "Hewlett-Packard UHCI root hub" rev 1.00/1.00 addr 1 ichpcib0 at pci0 dev 31 function 0 "Intel 6321ESB LPC" rev 0x09: PM disabled pciide0 at pci0 dev 31 function 1 "Intel 6321ESB IDE" rev 0x09: DMA, channel 0 configured to compatibility, channel 1 configured to compatibility atapiscsi0 at pciide0 channel 0 drive 0 scsibus1 at atapiscsi0: 2 targets cd0 at scsibus1 targ 0 lun 0: <HL-DT-ST, DVDRAM GSA-T40L, KS03> ATAPI 5/cdrom removable cd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 2 pciide0: channel 1 disabled (no drives) usb2 at uhci0: USB revision 1.0 uhub2 at usb2 "Intel UHCI root hub" rev 1.00/1.00 addr 1 usb3 at uhci1: USB revision 1.0 uhub3 at usb3 "Intel UHCI root hub" rev 1.00/1.00 addr 1 usb4 at uhci2: USB revision 1.0 uhub4 at usb4 "Intel UHCI root hub" rev 1.00/1.00 addr 1 usb5 at uhci3: USB revision 1.0 uhub5 at usb5 "Intel UHCI root hub" rev 1.00/1.00 addr 1 isa0 at ichpcib0 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 com1: probed fifo depth: 0 bytes 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 uhidev0 at uhub1 port 1 configuration 1 interface 0 "HP Virtual Keyboard" rev 1.10/0.02 addr 2 uhidev0: iclass 3/1 ukbd0 at uhidev0: 8 variable keys, 6 key codes, country code 33 wskbd1 at ukbd0 mux 1 wskbd1: connecting to wsdisplay0 uhidev1 at uhub1 port 1 configuration 1 interface 1 "HP Virtual Keyboard" rev 1.10/0.02 addr 2 uhidev1: iclass 3/1 ums0 at uhidev1: 3 buttons wsmouse0 at ums0 mux 0 uhidev2 at uhub4 port 1 configuration 1 interface 0 "NOVATEK USB Keyboard" rev 1.10/1.04 addr 2 uhidev2: iclass 3/1 ukbd1 at uhidev2: 8 variable keys, 6 key codes wskbd2 at ukbd1 mux 1 wskbd2: connecting to wsdisplay0 uhidev3 at uhub4 port 1 configuration 1 interface 1 "NOVATEK USB Keyboard" rev 1.10/1.04 addr 2 uhidev3: iclass 3/0, 2 report ids uhid0 at uhidev3 reportid 1: input=1, output=0, feature=0 uhid1 at uhidev3 reportid 2: input=3, output=0, feature=0 vscsi0 at root scsibus2 at vscsi0: 256 targets softraid0 at root scsibus3 at softraid0: 256 targets root on sd0a (4eaa98e52862e4b9.a) swap on sd0b dump on sd0b bnx0: address 00:22:64:a1:ed:d0 brgphy0 at bnx0 phy 1: BCM5708C 10/100/1000baseT PHY, rev. 6 bnx1: address 00:22:64:a1:5d:b8 brgphy1 at bnx1 phy 1: BCM5708C 10/100/1000baseT PHY, rev. 6 carp1: state transition: BACKUP -> MASTER carp2: state transition: BACKUP -> MASTER arp_rtrequest: bad gateway value arp_rtrequest: bad gateway value arp_rtrequest: bad gateway value arp_rtrequest: bad gateway value arp_rtrequest: bad gateway value arp_rtrequest: bad gateway value arp_rtrequest: bad gateway value carp1: state transition: MASTER -> BACKUP carp2: state transition: MASTER -> BACKUP