6

summary:

me@client:~$ sudo route del default ppp0
SIOCDELRT: No such process
me@client:~$ sudo route del default dev ppp0
SIOCDELRT: No such process
me@client:~$ sudo route del -net default dev ppp0
SIOCDELRT: No such process
me@client:~$ sudo route del -net default gw 10.144.15.234 dev ppp0
SIOCDELRT: No such process
me@client:~$ sudo route del -net default netmask 128.0.0.0 gw 10.144.15.234 dev ppp0
SIOCDELRT: No such process
me@client:~$ sudo route del -net default gw 0.0.0.0 dev ppp0
SIOCDELRT: No such process
me@client:~$ sudo route del -net default netmask 255.255.255.255 gw 0.0.0.0 dev ppp0
SIOCDELRT: No such process

details:

I'm trying to debug a VPN-related misconfiguration on a laptop (call it "the client") which is running

me@client:~$ cat /etc/debian_version
jessie/sid
me@client:~$ uname -rv
3.11-2-amd64 #1 SMP Debian 3.11.8-1 (2013-11-13)
me@client:~$ gcc --version | head -n 1
gcc (Debian 4.8.2-1) 4.8.2
me@client:~$ sudo route --version
[sudo] password for tlroche: 
net-tools 1.60
route 1.98 (2001-04-15)
+NEW_ADDRT +RTF_IRTT +RTF_REJECT +I18N
AF: (inet) +UNIX +INET +INET6 +IPX +AX25 +NETROM +X25 +ATALK +ECONET +ROSE 
HW:  +ETHER +ARC +SLIP +PPP +TUNNEL -TR +AX25 +NETROM +X25 +FR +ROSE +ASH +SIT +FDDI +HIPPI +HDLC/LAPB +EUI64 

On this client, I have started an OpenVPN client (after previously starting an OpenVPN server in the cloud), logged into a remote-access website, and used that site's web UI to connect to a (proprietary) F5 SSL VPN (which I want to tunnel through the OpenVPN). (More details on the design goal here and the problem configuration here.) This produces

me@client:~$ date ; sudo ifconfig
Thu Jan 22 11:48:43 EST 2015
eth0      Link encap:Ethernet  HWaddr <omitted/>
          inet addr:192.168.1.142  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: <omitted/>
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:10224715 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6011530 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:12886933501 (12.0 GiB)  TX bytes:677423768 (646.0 MiB)
          Interrupt:20 Memory:f2600000-f2620000 

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:65536  Metric:1
          RX packets:497 errors:0 dropped:0 overruns:0 frame:0
          TX packets:497 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:51273 (50.0 KiB)  TX bytes:51273 (50.0 KiB)

# Note I get slightly different IP#s for interface=ppp0 each time I run this scenario.

ppp0      Link encap:Point-to-Point Protocol  
          inet addr:10.144.15.234  P-t-P:10.144.0.1  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:6 errors:0 dropped:0 overruns:0 frame:0
          TX packets:18 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3 
          RX bytes:56 (56.0 B)  TX bytes:2418 (2.3 KiB)

tun0      Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  
          inet addr:10.8.0.6  P-t-P:10.8.0.5  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:4 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:304 (304.0 B)  TX bytes:304 (304.0 B)

me@client:~$ date ; sudo route -n
Thu Jan 22 11:48:48 EST 2015
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         10.144.15.100   128.0.0.0       UG    1      0        0 ppp0
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 eth0
10.144.0.1      0.0.0.0         255.255.255.255 UH    0      0        0 ppp0
128.0.0.0       10.144.15.100   128.0.0.0       UG    1      0        0 ppp0
134.67.15.30    10.8.0.5        255.255.255.255 UGH   1      0        0 tun0

Once at that point, I'm directed (IIUC) to delete the default route being set by the F5VPN (on interface=ppp0, for debugging. Furthermore, I need to do this quickly, because (and this is the problem with the current misconfiguration) the misconfiguration causes the OpenVPN tunnel to fail quickly, which breaks the situation I want to debug.

Hence it is quite infuriating that I cannot seem to find the correct route syntax to do this:

me@client:~$ sudo route del default ppp0
SIOCDELRT: No such process

me@client:~$ sudo route del default dev ppp0
SIOCDELRT: No such process

me@client:~$ sudo route del -net default dev ppp0
SIOCDELRT: No such process

me@client:~$ sudo route del -net default gw 10.144.15.234 dev ppp0
SIOCDELRT: No such process

me@client:~$ sudo route del -net default netmask 128.0.0.0 gw 10.144.15.234 dev ppp0
SIOCDELRT: No such process

me@client:~$ sudo route del -net default gw 0.0.0.0 dev ppp0
SIOCDELRT: No such process

me@client:~$ sudo route del -net default netmask 255.255.255.255 gw 0.0.0.0 dev ppp0
SIOCDELRT: No such process

info route is not helping, nor are my websearches finding helpful doc. (Both cases probably due to my lack of networking experience.) What am I doing wrong?

16

According to the routing table you have included in your question, you do not have a default route pointing to ppp0, so that's why you can't delete it. ("No such process" here means "No such route").

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         10.144.15.100   128.0.0.0       UG    1      0        0 ppp0
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 eth0

That's a route to 0.0.0.0/1 (NOT a default route, a default route is 0.0.0.0/0) pointing to 10.144.15.100 which uses ppp0, plus a default route pointing to 192.168.1.1 which goes out eth0.

By the way, on Linux, you should use the ip command instead of ifconfig, route, and others. The syntax and output formats used by ip are much more intuitive and easy to understand and use.

You should be able to see the above two routes (and all the others) with ip route and delete them with, respectively:

ip route del 0.0.0.0/1 via 10.144.15.100
ip route del default via 192.168.1.1
  • 1
    Thanks for the pointer to ip route and to tty1.net for teaching me about ip link. I am definitely finding those easier to use and parse! – TomRoche Jan 23 '15 at 16:48
  • Note also followup question (regarding latency observed in route deletion) here. – TomRoche Jan 23 '15 at 17:47

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