[4042] in linux-net channel archive
UDB Ethernet problem, part 2
daemon@ATHENA.MIT.EDU (Joshua M. Thompson)
Fri Aug 16 06:15:27 1996
Date: Thu, 15 Aug 1996 19:14:58 -0400 (EDT)
From: "Joshua M. Thompson" <invid@optera.com>
To: axp-list@redhat.com, linux-net@vger.rutgers.edu
(I'm sending this to linux-net as well now, because this is a _very_
strange networking problem)
Quick recap: DEC Alpha Universal Desktop box, running RedHat 3.0.3 but
with kernel 2.0.12 with DE4x5 driver (also used to run 2.0.11 with Tulip
driver, with same results). The problem is that at random times, my
Ethernet connection (UTP) goes "dead".
The last time this happened, I did some experimentation and discovered
some interesting facts about this problem :
1. The cabling seems OK. The hub carrier light is on, and the DEC senses
the carrier on its end as well (because if I unplug the cable, then I get
the "media is unconnected!" message). Generally if I do this plug/unplug
thing enough it will start working again, at which point no amount of
tugging on cables will make it go away (ie, no loose cables are evident).
2. If I "ping -f" a host that is still in the ARP table, I see activity
lights on teh UDB's hub port and on the hub port for the destination
machine. This means packets _are_ going out, and packets _are_ coming
back, but the DEC is either ignoring them or not seeing them. Eventually
my ARP entries time out so this stops working.
3. Occasionally a packet or two DOES get through, and I'll get a packet
or two back from a ping (plus refreshed ARP entries).
and now...the part that baffles me...
4. If I leave a ping running (not ping -f, just plain ping) and then
start doing the plug/unplug thing with the Ethernet cable, then when it
_does_ start working I get _all_ my ping respones. The first 10 or 20
have ping times on the order of tens of seconds (10,000s of ms). To me
this seems to indicate the DEC _did_ receive all those packets, but it
just buffered them until something I did "unclogged" it. If it weren't
for this strange behavior I would just go with the assumption that my DEC
is broken.
Unfortunately I don't have the necessary tools (or knowledge) to snoop
the Ethernet to see what's going on beyond what I've described here. I'm
thinking maybe there is a receive buffer problem of some sort, either on
the Ethernet hardware itself or in the networking code somewhere. I'm
including my kernel configuration below so you can see what my driver
setup looks like. If anybody has _any_ ideas I'd love to hear them,
because I'm about to pull my hair out with this one!
#
# Automatically generated make config: don't edit
#
#
# Code maturity level options
#
CONFIG_EXPERIMENTAL=y
#
# Loadable module support
#
CONFIG_MODULES=y
CONFIG_MODVERSIONS=y
# CONFIG_KERNELD is not set
#
# General setup
#
CONFIG_NATIVE=y
# CONFIG_ALPHA_AVANTI is not set
# CONFIG_ALPHA_XL is not set
# CONFIG_ALPHA_XLT is not set
# CONFIG_ALPHA_CABRIOLET is not set
# CONFIG_ALPHA_EB66 is not set
# CONFIG_ALPHA_EB66P is not set
# CONFIG_ALPHA_EB64P is not set
# CONFIG_ALPHA_EB164 is not set
# CONFIG_ALPHA_PC164 is not set
# CONFIG_ALPHA_JENSEN is not set
CONFIG_ALPHA_NONAME=y
# CONFIG_ALPHA_MIKASA is not set
# CONFIG_ALPHA_ALCOR is not set
# CONFIG_ALPHA_P2K is not set
CONFIG_PCI=y
CONFIG_ALPHA_LCA=y
CONFIG_ALPHA_NEED_ROUNDING_EMULATION=y
# CONFIG_SERIAL_ECHO is not set
CONFIG_TGA_CONSOLE=y
CONFIG_PCI_OPTIMIZE=y
CONFIG_NET=y
CONFIG_SYSVIPC=y
CONFIG_BINFMT_AOUT=y
CONFIG_BINFMT_ELF=y
#
# Floppy, IDE, and other block devices
#
CONFIG_BLK_DEV_FD=y
# CONFIG_BLK_DEV_IDE is not set
#
# Please see Documentation/ide.txt for help/info on IDE drives
#
# CONFIG_BLK_DEV_HD_ONLY is not set
#
# Additional Block Devices
#
CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_MD=y
CONFIG_MD_LINEAR=y
CONFIG_MD_STRIPED=y
CONFIG_BLK_DEV_RAM=y
# CONFIG_BLK_DEV_INITRD is not set
# CONFIG_BLK_DEV_XD is not set
# CONFIG_BLK_DEV_HD is not set
#
# Networking options
#
# CONFIG_FIREWALL is not set
CONFIG_NET_ALIAS=y
CONFIG_INET=y
CONFIG_IP_FORWARD=y
CONFIG_IP_MULTICAST=y
# CONFIG_IP_ACCT is not set
CONFIG_IP_ROUTER=y
CONFIG_NET_IPIP=m
CONFIG_IP_MROUTE=y
CONFIG_IP_ALIAS=y
#
# (it is safe to leave these untouched)
#
# CONFIG_INET_PCTCP is not set
# CONFIG_INET_RARP is not set
# CONFIG_NO_PATH_MTU_DISCOVERY is not set
CONFIG_IP_NOSR=y
CONFIG_SKB_LARGE=y
#
#
#
CONFIG_IPX=m
CONFIG_IPX_INTERN=y
CONFIG_ATALK=m
# CONFIG_AX25 is not set
# CONFIG_BRIDGE is not set
# CONFIG_NETLINK is not set
#
# SCSI support
#
CONFIG_SCSI=y
#
# SCSI support type (disk, tape, CD-ROM)
#
CONFIG_BLK_DEV_SD=y
CONFIG_CHR_DEV_ST=y
CONFIG_BLK_DEV_SR=y
CONFIG_CHR_DEV_SG=y
#
# Some SCSI devices (e.g. CD jukebox) support multiple LUNs
#
# CONFIG_SCSI_MULTI_LUN is not set
CONFIG_SCSI_CONSTANTS=y
#
# SCSI low-level drivers
#
# CONFIG_SCSI_7000FASST is not set
# CONFIG_SCSI_AHA152X is not set
# CONFIG_SCSI_AHA1542 is not set
# CONFIG_SCSI_AHA1740 is not set
# CONFIG_SCSI_AIC7XXX is not set
# CONFIG_SCSI_ADVANSYS is not set
# CONFIG_SCSI_IN2000 is not set
# CONFIG_SCSI_AM53C974 is not set
# CONFIG_SCSI_BUSLOGIC is not set
# CONFIG_SCSI_DTC3280 is not set
# CONFIG_SCSI_EATA is not set
# CONFIG_SCSI_EATA_DMA is not set
# CONFIG_SCSI_EATA_PIO is not set
# CONFIG_SCSI_FUTURE_DOMAIN is not set
# CONFIG_SCSI_GENERIC_NCR5380 is not set
# CONFIG_SCSI_NCR53C406A is not set
CONFIG_SCSI_NCR53C7xx=y
# CONFIG_SCSI_NCR53C7xx_sync is not set
# CONFIG_SCSI_NCR53C7xx_FAST is not set
# CONFIG_SCSI_NCR53C7xx_DISCONNECT is not set
# CONFIG_SCSI_PPA is not set
# CONFIG_SCSI_PAS16 is not set
# CONFIG_SCSI_QLOGIC_FAS is not set
# CONFIG_SCSI_QLOGIC_ISP is not set
# CONFIG_SCSI_SEAGATE is not set
# CONFIG_SCSI_T128 is not set
# CONFIG_SCSI_U14_34F is not set
# CONFIG_SCSI_ULTRASTOR is not set
#
# Network device support
#
CONFIG_NETDEVICES=y
CONFIG_DUMMY=m
CONFIG_EQUALIZER=m
# CONFIG_DLCI is not set
CONFIG_PLIP=m
CONFIG_PPP=y
#
# CCP compressors for PPP are only built as modules.
#
CONFIG_SLIP=m
CONFIG_SLIP_COMPRESSED=y
# CONFIG_SLIP_SMART is not set
# CONFIG_SLIP_MODE_SLIP6 is not set
# CONFIG_NET_RADIO is not set
CONFIG_NET_ETHERNET=y
# CONFIG_NET_VENDOR_3COM is not set
# CONFIG_LANCE is not set
# CONFIG_NET_VENDOR_SMC is not set
# CONFIG_NET_ISA is not set
CONFIG_NET_EISA=y
# CONFIG_AC3200 is not set
# CONFIG_APRICOT is not set
CONFIG_DE4X5=y
# CONFIG_DEC_ELCP is not set
# CONFIG_DGRS is not set
# CONFIG_ZNET is not set
# CONFIG_NET_POCKET is not set
# CONFIG_TR is not set
# CONFIG_ARCNET is not set
#
# ISDN subsystem
#
# CONFIG_ISDN is not set
#
# CD-ROM drivers (not for SCSI or IDE/ATAPI drives)
#
# CONFIG_CD_NO_IDESCSI is not set
#
# Filesystems
#
CONFIG_QUOTA=y
# CONFIG_LOCK_MANDATORY is not set
CONFIG_MINIX_FS=y
# CONFIG_EXT_FS is not set
CONFIG_EXT2_FS=y
CONFIG_XIA_FS=y
CONFIG_FAT_FS=y
CONFIG_MSDOS_FS=y
CONFIG_VFAT_FS=y
CONFIG_UMSDOS_FS=y
CONFIG_PROC_FS=y
CONFIG_NFS_FS=y
# CONFIG_ROOT_NFS is not set
CONFIG_SMB_FS=y
CONFIG_SMB_LONG=y
CONFIG_NCP_FS=m
CONFIG_ISO9660_FS=y
# CONFIG_HPFS_FS is not set
# CONFIG_SYSV_FS is not set
# CONFIG_AFFS_FS is not set
# CONFIG_UFS_FS is not set
#
# Character devices
#
CONFIG_SERIAL=y
# CONFIG_DIGI is not set
# CONFIG_CYCLADES is not set
# CONFIG_STALDRV is not set
# CONFIG_RISCOM8 is not set
CONFIG_PRINTER=y
CONFIG_MOUSE=y
# CONFIG_ATIXL_BUSMOUSE is not set
# CONFIG_BUSMOUSE is not set
# CONFIG_MS_BUSMOUSE is not set
CONFIG_PSMOUSE=y
# CONFIG_82C710_MOUSE is not set
# CONFIG_UMISC is not set
# CONFIG_QIC02_TAPE is not set
# CONFIG_FTAPE is not set
# CONFIG_APM is not set
# CONFIG_WATCHDOG is not set
CONFIG_RTC=y
#
# Sound
#
CONFIG_SOUND=y
# CONFIG_PAS is not set
# CONFIG_SB is not set
# CONFIG_ADLIB is not set
# CONFIG_GUS is not set
# CONFIG_MPU401 is not set
# CONFIG_UART6850 is not set
# CONFIG_PSS is not set
# CONFIG_GUS16 is not set
# CONFIG_GUSMAX is not set
CONFIG_MSS=y
# CONFIG_SSCAPE is not set
# CONFIG_TRIX is not set
# CONFIG_MAD16 is not set
# CONFIG_CS4232 is not set
# CONFIG_MAUI is not set
CONFIG_AUDIO=y
# CONFIG_MIDI is not set
# CONFIG_YM3812 is not set
MSS_BASE=530
MSS_IRQ=9
MSS_DMA=3
DSP_BUFFSIZE=65536
# CONFIG_LOWLEVEL_SOUND is not set
#
# Kernel hacking
#
# CONFIG_PROFILE is not set
--
invid@optera.com | We are Grey
http://www.optera.com/~invid | We stand between the Candle and the Star
| Between the Darkness and the Light
