I am attempting to build an IPv4/IPv6 router. I have put a 2nd ethernet card in a box. I have one Ethernet card attached to my network and the other to a switch with nothing else there just so the link comes up for testing. When I have the built-in Ethernet attached to my network, I get pings around 60ms. The other card, btw, does not have any IP addresses configed. When I switch the cards around, the addon card attached to my network, I get pings that alternate with one being ~1488ms and the next 488ms! This is regular. This is the 2nd card I have tried. The 1st one was getting ping times of 1900ms/900ms. I have played around with the IRQ for the 2nd card. The 1st card I tried I was limited to 9,10, or 11. The card I am using now allows 3, 4, or 7 (btw, I have disabled serial and parallel ports). Any Idea where I should look to fix this?
Robert Moskowitz wrote:> Any Idea where I should look to fix this?- What version of CentOS? - What type of network card? - What driver is it using? - What type of device is on the other end of the network card?(Switch, hub, router etc) - Can you verify that the speed and duplex settings match on both ends of the connection? - I assume the ping you are running is only 1 or 2(if there's a hub/switch in between) hops away? - Any errors reported by ifconfig ? any collisions? - Try replacing the card itself? maybe it is bad. nate
nate wrote:> Robert Moskowitz wrote: > > >> Any Idea where I should look to fix this? >> > > - What version of CentOS? >5.2> - What type of network card? >Intel the first time, DLink (Realtek) currently. Both 10/100Mb> - What driver is it using? >How do I tell?> - What type of device is on the other end of the network card?(Switch, hub, > router etc) >The card is plugged into a switch. All boxes plugged into the switch get similar PING results. Good with the internal (also Intel) card, bad/very_bad with the PCI ethernet card.> - Can you verify that the speed and duplex settings match on both ends of > the connection? >The switch has its 100Mb LED on. One of the switch ports has my Speedstream router which is only 10Mb, so we can believe the 100Mb LED. This is a dumb switch (my public network, so I am not going to plug into one of my Procurves).> - I assume the ping you are running is only 1 or 2(if there's a hub/switch > in between) hops away? >I have done it 1 hop (directly attached boxes), 2 hops, and somewhere out there on the net (198.6.1.2, a great system to use as an emergency DNS server).> - Any errors reported by ifconfig ? any collisions? >No and no. eth1 Link encap:Ethernet HWaddr 00:50:BA:42:82:49 inet addr:208.83.67.132 Bcast:208.83.67.135 Mask:255.255.255.248 inet6 addr: fe80::250:baff:fe42:8249/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1709 errors:0 dropped:0 overruns:0 frame:0 TX packets:1033 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:535351 (522.8 KiB) TX bytes:117321 (114.5 KiB) Interrupt:10 Base address:0xa000 ho, ho. MTU of 1500. Is this not doing MTU path discovery? But these are little PINGs so there should not be any frag problems (my WAN link is PPPoE, so you want pathMTU or have to hard config everything to 1415bytes per the pppoe man pages).> - Try replacing the card itself? maybe it is bad. >On my 2nd card already.
Warren Young wrote:> Robert Moskowitz wrote: >> >> I get pings around 60ms. > > Pings within the same LAN? If so, that's slow even for 100BaseT. It > should be under 10 ms.Well, perhaps I did not test everything out with the good card. MIght have been doing only 2 hop tests. But with the bad one, it is bad.> >> When I switch the cards around, the addon card attached to my >> network, I get pings that alternate with one being ~1488ms and the >> next 488ms! This is regular. > > Have you removed the cabling from consideration? And, do you know you > have good cabling, tested as following the wiring standards? Hand-made > cables are particularly suspect, if made by someone who doesn't know > what TIA/EIA 568 is, for example.Some cables are hand made, some purchased. All tested with my cable tester. I know all too well the various cabling standards.> >> I have played around with the IRQ for the 2nd card. The 1st card I >> tried I was limited to 9,10, or 11. The card I am using now allows >> 3, 4, or 7 (btw, I have disabled serial and parallel ports). > > None of this should matter in the PCI world, unless you're using > really old hardware, which didn't properly support IRQ sharing.It is old hardware. Compaq SFFs going back a number of years.> >>> - What driver is it using? >> >> How do I tell? > > grep eth0 /etc/modprobe.confGood card: alias eth0 e100 Bad card: alias eth1 8139too> > or scan through the output of the dmesg command, looking for stuff > that appears near "eth0".e100: Intel(R) PRO/100 Network Driver, 3.5.10-k2-NAPI e100: Copyright(c) 1999-2005 Intel Corporation ACPI: PCI Interrupt 0000:00:0a.0[A] -> Link [LNKD] -> GSI 10 (level, low) -> IRQ 10 e100: eth0: e100_probe: addr 0x41200000, irq 10, MAC addr 00:50:8B:00:43:B3 8139cp: 10/100 PCI Ethernet driver v1.2 (Mar 22, 2004) 8139cp 0000:00:0e.0: This (id 10ec:8139 rev 10) is not an 8139C+ compatible chip 8139cp 0000:00:0e.0: Try the "8139too" driver instead. input: PC Speaker as /class/input/input2 8139too Fast Ethernet driver 0.9.27 ACPI: PCI Interrupt 0000:00:0e.0[A] -> Link [LNKD] -> GSI 10 (level, low) -> IRQ 10 eth1: RealTek RTL8139 at 0xd08fa000, 00:50:ba:42:82:49, IRQ 10 eth1: Identified 8139 chip type 'RTL-8139B' The IRQs above are overrides on the BIOS settings of 11 and 3 respectively.> >>> - Can you verify that the speed and duplex settings match on both >>> ends of >>> the connection? >> >> The switch has its 100Mb LED on. One of the switch ports has my >> Speedstream router which is only 10Mb, so we can believe the 100Mb >> LED. This is a dumb switch (my public network, so I am not going to >> plug into one of my Procurves). > > That covers speed, but doesn't say anything about the duplex setting. > You should see this mentioned near the Ethernet driver load lines in > dmesg, too.Do you see anything in the lines I pasted above? Those are the only ones from dmesg.> >> ho, ho. MTU of 1500. Is this not doing MTU path discovery? > > PMTU-D is done per-connection at the TCP layer, not statically down at > L2.That I know, just thought there would be some indication in ifconfig. But thinking about it, I am not supprised there is not.
Nicolas Thierry-Mieg wrote:> > > Robert Moskowitz wrote: >>> That covers speed, but doesn't say anything about the duplex >>> setting. You should see this mentioned near the Ethernet driver load >>> lines in dmesg, too. >> >> Do you see anything in the lines I pasted above? Those are the only >> ones from dmesg. > > try: > ethtool eth0thanks: ethtool eth1 Settings for eth1: Supported ports: [ TP MII ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full Port: MII PHYAD: 32 Transceiver: internal Auto-negotiation: on Supports Wake-on: pumbg Wake-on: d Current message level: 0x00000007 (7) Link detected: yes
NiftyClusters Mitch wrote:> Good list: > Also add multiple runs of "traceroute" and also try ping, ping -f , > ping -A and ping -R. See also ping6 > If routes are dynamic we have one answer to the problem, I would > expect traceroute to have 'one' answer on a simple net. > If packets are falling on the floor then we need to know why. > > The different invocations of ping can tell you if packets drop at slow > or fast transfer rates. > ping -R is slightly different than traceroute but if the return routes > flip one way then the > other we should know why. > > Watch out for /etc/sysconfig/network-scripts/ifcfg* where hardware addresses, > subnet masks, device driver links/ names etc. no longer match the hardware > when things move. >More, watch out for /etc/sysconfig/networking/devices where configs that you thought you deleted live on to get you when your run system-config-network. I just could not figure out, for a while, why when I deleted /etc/sysconfig/network-scripts/ifcfg-eth1.bak it would be right back there!> Consider snooping packets on the link to see if all is as you expect. I keep an > old, slow network hub (not a switching hub) for the times when I want > to see the bits on the wire and > not the bits that the local driver is able to show me.I have one as well. It is so hard to find them anymore....