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I'm not sure it's a routing question - my understanding is too basic. There is the issue:

I am connected to a network as 10.103.38.4 and route goes per default per:

10.103.38.0/24 dev enp10s0 proto kernel scope link src 10.103.38.4 metric 100 
169.254.0.0/16 dev enp10s0 scope link metric 1000 
192.168.13.148 via 10.103.38.1 dev enp10s0 proto dhcp metric 100

I understand the gateway / default route is 10.103.38.1 and packets are filtered through a nasty login, every time.

However, there are other hosts on the network, which directly connect to the outside world i.e. 10.103.108.1. I can see this latter host and connect to it.

What to do to send the default route through the 10.103.108.1 - if i set it up as a default route, the network is unreachable.

WhiteWinterWolf
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The Arkaroo
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  • It is not clear at all what you are asking. Mind you a host/gateway having a private IP address is not directly connected to the Internet. Please do not write posts in a rush if you need help. Your post is difficult to follow, and what is your doubt is not entirely clear. Our focus is also into answering specific doubts, and not writing tutorials. please read our faq. – Rui F Ribeiro Oct 22 '17 at 10:20

1 Answers1

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Here is your issue as I understand it:

  • Your IP is 10.103.38.4.
  • You are part of the network 10.103.38.0/24 which uses the default router 10.103.38.1.
  • This router requires a annoying login to access the Internet.
  • Other networks such as 10.103.108.0/24 have access to the Internet without requiring login, their default router (10.103.108.1) is accessible to you.

So, first thing first, I will take your question from a pure theoretical perspective as it raises an interesting concept since, otherwise, it would mean you are trying to bypass a local policy which is no good.

As a stated above, the other routers are in fact located on different networks, this means that you have to go through your main router 10.103.38.1 to reach the other routers like 10.103.108.1, you cannot reach them directly.

What you may wonder is if there is a way to use 10.103.108.1 as your first hop router, but then instead of directly going to the Internet ask it to first go through 10.103.108.1 (internal network so no login required) and only then go to the Internet (10.103.108.1 used as exit node, so login bypassed).

Such feature technically exists and is called source routing. Normally it's up to the router to determine the best route, but source routing allows the initial sender to impose the route that its packets should take.

Obviously, this feature is usually disabled everywhere precisely to avoid tricky people to exploit it maliciously ;).

WhiteWinterWolf
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  • The 10.103.108.1 host will also have to be configured to act as a router, i.e. it should be able to forward received packets that are not destined to it. Forwarding is usually disabled. – Johan Myréen Oct 22 '17 at 13:17
  • @JohanMyréen: 10.103.108.1 is most likely the default router for the 10.103.108.0/24 network (relying both on OP message stating it "connect to the outside world" and given the apparent naming scheme, as we know from OP message that 10.103.38.1 is the default router for the 10.103.38.0/24 network). – WhiteWinterWolf Oct 22 '17 at 13:22