On Sat, 18 Jul 2015 22:37:30 -0700 Gordon Messmer wrote:> On 07/18/2015 10:12 PM, Frank Cox wrote: > > Interesting. But since it's still exactly the same, it's still not > > working; it still fails in exactly the same way too. > > Yes, but that means you need to start with the standard troubleshooting > stuff. Do you have link? Is the Ethernet cable working?[root at audio ~]# ip link 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:26:5a:07:f0:da brd ff:ff:ff:ff:ff:ff 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:26:5a:07:ef:8d brd ff:ff:ff:ff:ff:ff 4: eth2: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:40:05:86:66:4a brd ff:ff:ff:ff:ff:ff 5: sit0: <NOARP> mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0 I double-checked that I had the ethernet cable plugged into the right port on the server by unplugging it and then eth1 said "NO CARRIER". As far as I know, that means that the cable and port are working. Do you see > any traffic if you run "tcpdump -nn -i eth1"? I see no traffic on eth1 with that command until I log into another session and type "ping google.com". Then I get this output: [root at audio ~]# tcpdump -nn -i eth1 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth1, link-type EN10MB (Ethernet), capture size 96 bytes 00:11:00.412188 arp who-has 204.83.15.254 tell 204.83.15.1 00:11:01.412135 arp who-has 204.83.15.254 tell 204.83.15.1 00:11:02.412112 arp who-has 204.83.15.254 tell 204.83.15.1 3 packets captured 3 packets received by filter 0 packets dropped by kernel Double-check your IP address and gateway in the configuration file. Seems to be correct.> Is the gateway's MAC address listed in the output of "arp"?Apparently not. [root at audio ~]# arp Address HWtype HWaddress Flags Mask Iface 192.168.1.1 ether 00:24:01:F3:93:21 C eth0 204.83.15.254 (incomplete) eth1 I don't know what that means; this is the first time I ever typed the arp command. -- MELVILLE THEATRE ~ Real D 3D Digital Cinema ~ www.melvilletheatre.com
Am 19.07.2015 um 08:13 schrieb Frank Cox:> On Sat, 18 Jul 2015 22:37:30 -0700 > Gordon Messmer wrote:[ ... ]> Do you see > any traffic if you run "tcpdump -nn -i eth1"? > > I see no traffic on eth1 with that command until I log into another session and type "ping google.com". Then I get this output: > > [root at audio ~]# tcpdump -nn -i eth1 > tcpdump: verbose output suppressed, use -v or -vv for full protocol decode > listening on eth1, link-type EN10MB (Ethernet), capture size 96 bytes > 00:11:00.412188 arp who-has 204.83.15.254 tell 204.83.15.1 > 00:11:01.412135 arp who-has 204.83.15.254 tell 204.83.15.1 > 00:11:02.412112 arp who-has 204.83.15.254 tell 204.83.15.1No response to the arp queries.> 3 packets captured > 3 packets received by filter > 0 packets dropped by kernel > > Double-check your IP address and gateway in the configuration file. > > Seems to be correct. > >> Is the gateway's MAC address listed in the output of "arp"? > > Apparently not. > > [root at audio ~]# arp > Address HWtype HWaddress Flags Mask Iface > 192.168.1.1 ether 00:24:01:F3:93:21 C eth0 > 204.83.15.254 (incomplete) eth1Again, no ARP result.> I don't know what that means; this is the first time I ever typed the arp command.Clearly your gateway 204.83.15.254 does not act like it should. Look broken or misconfigured, at least from within your network. Alexander
On 07/18/2015 11:13 PM, Frank Cox wrote:> [root at audio ~]# tcpdump -nn -i eth1 > tcpdump: verbose output suppressed, use -v or -vv for full protocol decode > listening on eth1, link-type EN10MB (Ethernet), capture size 96 bytes > 00:11:00.412188 arp who-has 204.83.15.254 tell 204.83.15.1 > 00:11:01.412135 arp who-has 204.83.15.254 tell 204.83.15.1...>> Is the gateway's MAC address listed in the output of "arp"? > [root at audio ~]# arp > Address HWtype HWaddress Flags Mask Iface > 204.83.15.254 (incomplete) eth1 > > I don't know what that means; this is the first time I ever typed the arp command.When you're using Ethernet, packets are transmitted between cards using the MAC address of the recipient's interface. IPv4 resolves hardware addresses (MAC address) using the ARP protocol. In order to send a packet to 204.83.15.254, a host on the same network segment sends a broadcast request (arp who-has) request for the hardware address associated with that IPv4 address. The host with that IPv4 address should send a unicast reply to the host that sent the request. Understanding arp is essential to troubleshooting IPv4 and Ethernet. (IPv6 does not use ARP to resolve MAC addresses) Your host, 204.83.15.1 is on a /24 network with its gateway, 204.83.15.254. I would expect that a /24 network would probably have more than two hosts. If that's the case, it would be extremely unusual to see no broadcast traffic when you run "tcpdump" on that interface. Normally you'd see arp broadcast requests every few seconds, even if you didn't see any other traffic. It's hard to say specifically what the problem might be without knowing more about the physical topology of your network, but the most likely problems are that you're connected to a network segment with no other hosts, or that you're on a segment with only one host (the gateway) which has no need to broadcast anything and is on a different address than you expect, or that your cable is defective (even with link), or that the device your host is physically attached to is defective.
On Sun, 19 Jul 2015 17:27:09 +0200 Alexander Dalloz wrote:> Clearly your gateway 204.83.15.254 does not act like it should. Look > broken or misconfigured, at least from within your network.This server has three network cards in it. I just disabled (unconfigured) eth1 and configured eth2 with the external IP address and whatnot. Plugged in the modem to eth2 and away she goes. Everything works as it should. Cranked up the streaming audio and rock on! So I apparently have a hardware issue; eth1 has failed in some strange way. Oh well. I'm not going to worry about replacing it right away since I'm just using two network connections at the moment anyway. I'm running a yum update on that machine right now (for the first time since it was shut off a year ago) and all appears to be well. Thanks to everyone for taking the time to look at my issue and provide input. I hate mysterious hardware failures. The only bad news is that the radio station has fallen off the air today for some reason, so all I have to stream from there is static. Oh well -- that end is NOT my problem. Thanks again for the assistance, folks! -- MELVILLE THEATRE ~ Real D 3D Digital Cinema ~ www.melvilletheatre.com