Apologies for letting this thread[1] drop--I was forced to handle other
interrupts for a few weeks. Basically, I need to make a networking
configuration work, but am currently (apparently) blocked by inability to set a
route. Details:
A brief summary of what I need to do to get back to work on a science
project[2] is
1. I must `ssh` from a Debian laptop through a firewall to a compute cluster,
where I can do the actual science.
2. The cluster's admins (aka "the agency") require use of an F5VPN to cross the
firewall, and maintain the F5VPN server through which I must connect.
3. The F5VPN client is entirely {proprietary, blackbox to me, nonconfigurable
by me}.
4. The agency (now) requires "security" features which I'm attempting to meet
using a cloud node (on which I have root, and which also runs Debian and an
OpenVPN server) as a jumpbox.
5. Both the F5VPN and OpenVPN clients run on my laptop (on which I am sole
root).
(Full/gory details regarding networking requirements and history available
here[3], toy diagram here[4].) My current problem is, I'm not able to set
(i.e., `ip route add`) one of the routes I believe I need to make this VPN
configuration work, and thus meet my networking requirements. I get to that
point via the following sequence:
1. [initial routeset , start OpenVPN client] -> OpenVPN routeset
2. [OpenVPN routeset , start F5VPN client ] -> F5VPN-imposed routeset
3. delete F5VPN-imposed routeset
4. set F5VPN-through-OpenVPN routeset
Sequence details:
My laptop's "initial routeset" (i.e., what `ip route show`s after restarting
the laptop when connected to the modem) is
0: default via 192.168.1.1 dev eth0 proto static
1: 169.254.0.0/16 dev eth0 scope link metric 1000
2: 192.168.1.0/24 dev eth0 proto kernel scope link src LOCAL_IPN
(I'll parameterize some IP#s for clarity. E.g., in the above,
LOCAL_IPN==192.168.1.142 , i.e., the laptop's LAN IP#.) At this point, DNS (and
`ping`, etc) works, and if I browse to (e.g.) whatismyip.com I see my modem's
IP#==INITIAL_PUBLIC_IPN . After I
1. start the OpenVPN server process on my cloud node
2. start the OpenVPN client process on my laptop
I get the following "OpenVPN routeset":
0: 0.0.0.0/1 via OPENVPN_ENDPT_IPN dev tun0
1: default via 192.168.1.1 dev eth0 proto static
2: OPENVPN_GATEWAY_IPN via OPENVPN_ENDPT_IPN dev tun0
3: OPENVPN_ENDPT_IPN dev tun0 proto kernel scope link src OPENVPN_SRCPT_IPN
4: 128.0.0.0/1 via OPENVPN_ENDPT_IPN dev tun0
5: 169.254.0.0/16 dev eth0 scope link metric 1000
6: OPENVPN_PUBLIC_IPN via 192.168.1.1 dev eth0
7: 192.168.1.0/24 dev eth0 proto kernel scope link src LOCAL_IPN
(FWIW, I have never observed any change in the following IP#s, despite repeated
use:
OPENVPN_GATEWAY_IPN='10.8.0.1'
OPENVPN_ENDPT_IPN= '10.8.0.5'
OPENVPN_SRCPT_IPN= '10.8.0.6'
) As suggested by the OpenVPN routeset, my OpenVPN client (which is quite
"vanilla"[5]) adds a new link/interface=tun0, and subsequently other sites see
a new public IP#==OPENVPN_PUBLIC_IPN . DNS still works, and networking life is
good. But after I
1. login to the agency's remote-access website (RAW) using a special, F5-ed
browser[6]
2. use the RAW's web UI to connect to the F5VPN server
I get the following "F5VPN-imposed routeset":
0: 0.0.0.0/1 via F5VPN_ENDPT_IPN dev ppp0 proto none metric 1
1: default via 192.168.1.1 dev eth0 proto static
2: F5VPN_GATEWAY_IPN dev ppp0 proto kernel scope link src F5VPN_ENDPT_IPN
3: 128.0.0.0/1 via F5VPN_ENDPT_IPN dev ppp0 proto none metric 1
4: F5VPN_PUBLIC_IPN via OPENVPN_ENDPT_IPN dev tun0 proto none metric 1
(F5VPN_GATEWAY_IPN, F5VPN_ENDPT_IPN, and F5VPN_PUBLIC_IPN all seem to change
with each F5VPN use/connection.) At this point I also have a new
link/interface=ppp0. However, at this point I cannot either `ping` or DNS: e.g.,
$ ping -c 4 141.101.120.15 # == www.whatismyip.com
PING 141.101.120.15 (141.101.120.15) 56(84) bytes of data.
--- 141.101.120.15 ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3022ms
$ nslookup www.whatismyip.com
;; connection timed out; no servers could be reached
So it seems the F5VPN client cannot set routes that will work with the OpenVPN;
to be fair, that is probably because the F5VPN knows nothing about the OpenVPN.
Hence, after previous discussion (e.g., this post[7]), I first deleted (with
this code[8]) the F5VPN-imposed routeset, then tried to set the following
"F5VPN-through-OpenVPN routeset" (using this code[9]):
0: 192.168.1.0/24 dev eth0 proto kernel scope link src LOCAL_IPN
1: 0.0.0.0/1 via F5VPN_ENDPT_IPN dev ppp0 metric 1
2: default via 192.168.1.1 dev eth0 proto static
3: F5VPN_GATEWAY_IPN dev ppp0 proto kernel scope link src F5VPN_ENDPT_IPN
4: 128.0.0.0/1 via F5VPN_ENDPT_IPN dev ppp0 metric 1
5: OPENVPN_PUBLIC_IPN via 192.168.1.1 dev eth0
6: F5VPN_PUBLIC_IPN via OPENVPN_ENDPT_IPN dev tun0 metric 1
I can `ip route add` all of the above ... *except* the last route#=6! which
gets the response
> RTNETLINK answers: Network is unreachable
This appears to be a real failure, in that if I subsequently (i.e., immediately
after running the above script[9]) do
$ sudo ip route add ${F5VPN_PUBLIC_IPN} via ${OPENVPN_ENDPT_IPN} dev tun0
metric 1
from the commandline, I get the same failure. And, just to be clear, at this
point my networking is just as broken as before: both `ping` and DNS fail until
I disconnect from the F5VPN, stop the OpenVPN, and restore my initial routeset
and linkset.
So ... how to fix this? What am I doing wrong? Any assistance you can provide
is much appreciated! and will be paid-forward via the above code and wiki.
TIA, Tom Roche <[email protected]>
[1]: first post @ https://lists.debian.org/debian-user/2015/01/msg00732.html ,
last post before this one @
https://lists.debian.org/debian-user/2015/01/msg00905.html
[2]: https://bitbucket.org/tlroche/aqmeii-na_n2o/wiki/Home
[3]: https://bitbucket.org/tlroche/linode_jumpbox_config/wiki/Home
[4]:
https://bitbucket.org/tlroche/linode_jumpbox_config/wiki/Home#rst-header-new-architecture-diagram
[5]:
https://bitbucket.org/tlroche/linode_jumpbox_config/wiki/OpenVPN_install#rst-header-id5
[6]:
https://bitbucket.org/tlroche/linode_jumpbox_config/wiki/Home#rst-header-f5nap
[7]: https://lists.debian.org/debian-user/2015/01/msg00905.html
[8]:
https://bitbucket.org/tlroche/linode_jumpbox_config/raw/HEAD/scripts/delete_current_routes.sh
[9]:
https://bitbucket.org/tlroche/linode_jumpbox_config/raw/HEAD/scripts/set_F5VPN_routes.sh
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