This looks like another manifestation of the Linux arp differences from end user expectation.
Begin forwarded message: Date: Mon, 3 Sep 2007 08:19:26 -0700 (PDT) From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: [Bug 8975] New: Broadcasting fails when default gateway can't be reached. http://bugzilla.kernel.org/show_bug.cgi?id=8975 Summary: Broadcasting fails when default gateway can't be reached. Product: Networking Version: 2.5 KernelVersion: 2.6.22 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: IPV4 AssignedTo: [EMAIL PROTECTED] ReportedBy: [EMAIL PROTECTED] Most recent kernel where this bug did not occur: N/A (I tried with 2.6.18-4 and 2.6.22 Distribution: - Debian 4.0 2.6.18-4 kernel & custom-kernel 2.6.22 from Mainline - Hardware Environment: serv#lspci 00:00.0 Host bridge: VIA Technologies, Inc. VT82C693A/694x [Apollo PRO133x] (rev 44) 00:01.0 PCI bridge: VIA Technologies, Inc. VT82C598/694x [Apollo MVP3/Pro133x AGP] 00:07.0 ISA bridge: VIA Technologies, Inc. VT82C596 ISA [Mobile South] (rev 23) 00:07.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 10) 00:07.3 Host bridge: VIA Technologies, Inc. VT82C596 Power Management (rev 30) 00:09.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10) 01:00.0 VGA compatible controller: ATI Technologies Inc Rage 128 RL/VR AGP serv:~# lsmod Module Size Used by ipv6 213856 14 ipt_MASQUERADE 3584 1 iptable_nat 7044 1 ip_nat 16428 2 ipt_MASQUERADE,iptable_nat ip_conntrack 47156 3 ipt_MASQUERADE,iptable_nat,ip_nat nfnetlink 6680 2 ip_nat,ip_conntrack ip_tables 12104 1 iptable_nat x_tables 12932 3 ipt_MASQUERADE,iptable_nat,ip_tables dm_snapshot 15644 0 dm_mirror 18000 0 dm_mod 48952 2 dm_snapshot,dm_mirror loop 14216 0 serio_raw 6532 0 floppy 52004 0 i2c_viapro 8340 0 i2c_core 19472 1 i2c_viapro psmouse 34568 0 rtc 11572 0 via_agp 9728 1 agpgart 29360 1 via_agp shpchp 32796 0 pci_hotplug 28088 1 shpchp pcspkr 2816 0 evdev 9088 0 ext3 116488 2 jbd 47272 1 ext3 ide_disk 14848 4 via82cxxx 8452 0 [permanent] generic 5508 0 [permanent] ide_core 107760 3 ide_disk,via82cxxx,generic 8139cp 20736 0 8139too 24192 0 mii 5376 2 8139cp,8139too processor 23724 0 serv:~# cat /proc/interrupts CPU0 0: 798632 XT-PIC timer 1: 38 XT-PIC i8042 2: 0 XT-PIC cascade 6: 2 XT-PIC floppy 8: 1 XT-PIC rtc 10: 228692 XT-PIC eth0 14: 11482 XT-PIC ide0 NMI: 0 LOC: 0 ERR: 0 MIS: 0 Software Environment: serv:~# ifconfig eth0 Link encap:Ethernet HWaddr 00:C0:26:A0:C6:99 inet addr:192.168.0.10 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::2c0:26ff:fea0:c699/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:62020 errors:0 dropped:0 overruns:0 frame:0 TX packets:174169 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:10881985 (10.3 MiB) TX bytes:204869648 (195.3 MiB) Interrupt:10 Base address:0xe800 eth0:1 Link encap:Ethernet HWaddr 00:C0:26:A0:C6:99 inet addr:192.168.10.1 Bcast:192.168.10.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:10 Base address:0xe800 serv:~# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.10.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0 Problem Description: Broadcasting fail in next "unusual" cases: - default route points to any gateway (192.168.0.1). - The physical ethernet connection to the gateway is broke so ARP doesn't work. Steps to reproduce: Case 1: Router is connected: Client ------- switch -------- router | | Server Case 2: Router is diconnected: Client ------- switch router | | Server - I setup a DHCP server and a client machine tries to get an IP setup from it. - The client and the server always have a correct physical connection. - With the physical connection working fine (wire connected) everything works fine. - When the router get disconnected next happen: The Client never receives the broadcast data with the IP setup. Still, using tcpdump I can see the server trying to broadcast the data through physical interface eth0 -but such data never goes out the wire since the client hangs for ever). tcpdump also shows the server is trying to solve the ARP entry for the router IP. When I delete the default gateway (route del -net 0.0.0.0) everything works fine again. (Without the eth0:1 alias the behaviour is similar) Regards, Enrique -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
