| Unknown Object (User) | |
| Jan 8 2021, 9:15 AM |
Add Cisco style GRE keepalive support [0] using [1].
This is useful for tunnel up/down detection and is required by several DDoS mitigation providers.
[0] https://www.cisco.com/c/en/us/support/docs/ip/generic-routing-encapsulation-gre/118370-technote-gre-00.html
[1] https://github.com/Jamesits/linux-gre-keepalive
Why not use the mentioned method of sysctl`
VyOS 1.3: set system sysctl custom net.ipv4.conf.all.accept_local value 1
VyOS 1.4: set system sysctl parameter net.ipv4.conf.all.accept_local value 1
Or even limit this to your tunnel interface (tun10):
VyOS 1.3: set system sysctl custom net.ipv4.conf.tun10.accept_local value 1
VyOS 1.4: set system sysctl parameter net.ipv4.conf.tun10.accept_local value 1
It probably would make sense to add a real CLI note for this unter the tunnel interface.
See [1] from the previous post:
Note: If you don't want to install anything and don't care about some potential security problems, just enable the following 2 options to get native GRE keepalive support on Linux: […]
I care. Setting these sysctl parameters allows for relaying arbitrary traffic through the router.