Hi!
I am trying to use hping to chek the latency of our network. Somehow things are not going to plan and I thought someone might be able to shed some light on the subject.
Here is the setup: (the IP addresses gvien here are fake, but they do represent the correct state of the networking setup) vlan interface IP mask V2 eth0 192.168.20.20 32 V4 eth1 172.16.4.40 32 V6 eth2 172.16.6.60 32
The default route is set to eth1. The idea is to use eth2 for pinging only, the other two interfaces are used by another service and management access.
If I do: ping -c 2 -I eth2 74.125.39.147 or fping -c 2 -I eth2 74.125.39.147 It binds to eth2 and sends its ICMP probes via that interface with the IP on that interface.
If I do: hping3 -1 -c 2 -I eth2 74.125.39.147 -VD or [root@server ~]# hping3 -c 2 -I eth2 74.125.39.147 -VD DEBUG: if lo: Don't Match (but seems to be UP) DEBUG: if eth0: Don't Match (but seems to be UP) DEBUG: if eth1: Don't Match (but seems to be UP) DEBUG: if eth2: OK using eth2, addr: 172.16.6.60, MTU: 1500
It supposedly binds to eth2. But tcpdump tells another story. Packets get sent out via the default route (eth1) with the IP from eth2 set as the source address.
The same happens with tcptraceroute (tcptraceroute-1.5-0.beta7.el5.rf.i386.rpm).
I have tried various routing policies, but I have yet to find a solution that works. I have used iptables to log the packets in the OUTPUT chain, but they arrive there with the interface already set to eth1.
Can anyone help ?
Regards, Mitja Mihelic
From: Mitja Mihelič mitja.mihelic@arnes.si
I am trying to use hping to chek the latency of our network. Somehow things are not going to plan and I thought someone might be able to shed some light on the subject. Here is the setup: (the IP addresses gvien here are fake, but they do represent the correct state of the networking setup) vlan interface IP mask V2 eth0 192.168.20.20 32 V4 eth1 172.16.4.40 32 V6 eth2 172.16.6.60 32
The default route is set to eth1. The idea is to use eth2 for pinging only, the other two interfaces are used by another service and management access.
Could you show the ifconfig and route outputs...?
JD
On 09/30/2010 05:02 PM, John Doe wrote:
From: Mitja Miheličmitja.mihelic@arnes.si
I am trying to use hping to chek the latency of our network. Somehow things are not going to plan and I thought someone might be able to shed some light on the subject. Here is the setup: (the IP addresses gvien here are fake, but they do represent the correct state of the networking setup) vlan interface IP mask V2 eth0 192.168.20.20 32 V4 eth1 172.16.4.40 32 V6 eth2 172.16.6.60 32
The default route is set to eth1. The idea is to use eth2 for pinging only, the other two interfaces are used by another service and management access.
Could you show the ifconfig and route outputs...?
JD
The Centos version is 5.5.
This is the kernel we are using (http://rpms.mcnc.org/web100/el5/distro-compat/i386/): 2.6.18-164.15.1.el5.web100PAE #1 SMP Mon May 17 17:01:51 EDT 2010 i686 athlon i386 GNU/Linux
The IP addresses are presented as private addresses, netmasks are real.
Here is the ifconfig output: [root@server ~]# ifconfig eth0 Link encap:Ethernet HWaddr 00:16:35:82:45:A0 inet addr:192.168.254.236 Bcast:192.168.254.239 Mask:255.255.255.240 inet6 addr: fe80::216:35ff:fe82:45a0/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:139602 errors:0 dropped:0 overruns:0 frame:0 TX packets:58914 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:211203420 (201.4 MiB) TX bytes:4285647 (4.0 MiB) Interrupt:186 Memory:dc000000-dc012800
eth1 Link encap:Ethernet HWaddr 00:16:35:82:45:A2 inet addr:192.168.254.244 Bcast:192.168.254.247 Mask:255.255.255.248 inet6 addr: fe80::216:35ff:fe82:45a2/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:15 errors:0 dropped:0 overruns:0 frame:0 TX packets:14 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1130 (1.1 KiB) TX bytes:1116 (1.0 KiB) Interrupt:194 Memory:da000000-da012800
eth2 Link encap:Ethernet HWaddr 00:15:17:C5:84:4D inet addr:192.168.254.18 Bcast:192.168.254.23 Mask:255.255.255.248 inet6 addr: fe80::215:17ff:fec5:844d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:29 errors:0 dropped:0 overruns:0 frame:0 TX packets:18 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2280 (2.2 KiB) TX bytes:1236 (1.2 KiB) Memory:dfde0000-dfe00000
lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:21 errors:0 dropped:0 overruns:0 frame:0 TX packets:21 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:4240 (4.1 KiB) TX bytes:4240 (4.1 KiB)
And the route command output: [root@server ~]# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.18.122 192.168.254.225 255.255.255.255 UGH 0 0 0 eth0 192.168.254.16 0.0.0.0 255.255.255.248 U 0 0 0 eth2 192.168.254.240 0.0.0.0 255.255.255.248 U 0 0 0 eth1 192.168.18.160 192.168.254.225 255.255.255.240 UG 0 0 0 eth0 192.168.254.224 0.0.0.0 255.255.255.240 U 0 0 0 eth0 192.168.1.64 192.168.254.225 255.255.255.192 UG 0 0 0 eth0 192.168.1.128 192.168.254.225 255.255.255.128 UG 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth2 0.0.0.0 192.168.254.241 0.0.0.0 UG 0 0 0 eth1
-- Mitja
2010/10/1 Mitja Mihelič mitja.mihelic@arnes.si:
On 09/30/2010 05:02 PM, John Doe wrote:
From: Mitja Miheličmitja.mihelic@arnes.si
I am trying to use hping to chek the latency of our network. Somehow things are not going to plan and I thought someone might be able to shed some light on the subject. Here is the setup: (the IP addresses gvien here are fake, but they do represent the correct state of the networking setup) vlan interface IP mask V2 eth0 192.168.20.20 32 V4 eth1 172.16.4.40 32 V6 eth2 172.16.6.60 32
The default route is set to eth1. The idea is to use eth2 for pinging only, the other two interfaces are used by another service and management access.
Could you show the ifconfig and route outputs...?
JD
The Centos version is 5.5.
This is the kernel we are using (http://rpms.mcnc.org/web100/el5/distro-compat/i386/): 2.6.18-164.15.1.el5.web100PAE #1 SMP Mon May 17 17:01:51 EDT 2010 i686 athlon i386 GNU/Linux
The IP addresses are presented as private addresses, netmasks are real.
Here is the ifconfig output: [root@server ~]# ifconfig eth0 Link encap:Ethernet HWaddr 00:16:35:82:45:A0 inet addr:192.168.254.236 Bcast:192.168.254.239 Mask:255.255.255.240 inet6 addr: fe80::216:35ff:fe82:45a0/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:139602 errors:0 dropped:0 overruns:0 frame:0 TX packets:58914 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:211203420 (201.4 MiB) TX bytes:4285647 (4.0 MiB) Interrupt:186 Memory:dc000000-dc012800
eth1 Link encap:Ethernet HWaddr 00:16:35:82:45:A2 inet addr:192.168.254.244 Bcast:192.168.254.247 Mask:255.255.255.248 inet6 addr: fe80::216:35ff:fe82:45a2/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:15 errors:0 dropped:0 overruns:0 frame:0 TX packets:14 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1130 (1.1 KiB) TX bytes:1116 (1.0 KiB) Interrupt:194 Memory:da000000-da012800
eth2 Link encap:Ethernet HWaddr 00:15:17:C5:84:4D inet addr:192.168.254.18 Bcast:192.168.254.23 Mask:255.255.255.248 inet6 addr: fe80::215:17ff:fec5:844d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:29 errors:0 dropped:0 overruns:0 frame:0 TX packets:18 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2280 (2.2 KiB) TX bytes:1236 (1.2 KiB) Memory:dfde0000-dfe00000
lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:21 errors:0 dropped:0 overruns:0 frame:0 TX packets:21 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:4240 (4.1 KiB) TX bytes:4240 (4.1 KiB)
And the route command output: [root@server ~]# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.18.122 192.168.254.225 255.255.255.255 UGH 0 0 0 eth0 192.168.254.16 0.0.0.0 255.255.255.248 U 0 0 0 eth2 192.168.254.240 0.0.0.0 255.255.255.248 U 0 0 0 eth1 192.168.18.160 192.168.254.225 255.255.255.240 UG 0 0 0 eth0 192.168.254.224 0.0.0.0 255.255.255.240 U 0 0 0 eth0 192.168.1.64 192.168.254.225 255.255.255.192 UG 0 0 0 eth0 192.168.1.128 192.168.254.225 255.255.255.128 UG 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth2 0.0.0.0 192.168.254.241 0.0.0.0 UG 0 0 0 eth1
-- Mitja _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
This may be too late, but came across this searching for my old iproute conversations. Each NIC needs its own "source based route" otherwise, it will use the sytem wide default route. In other words, add "nic specific default routes" in addition to the "system wide default route".
Once you have nic specific source routes, you may notice a big difference between the following two seemingly identical commands: ping -I eth2 208.67.222.222 ping -I 192.168.x.y 208.67.222.222
-
John Doe -
Mitja Mihelič -
Rob Townley