What is the limit on the number of ip gre tunnels in linux?

Question

linux

I just can't figure out this number.

Answer 1

Something tells me that Linux does not tunnel through GRE. And, for example, pptpd. It turns out that the restriction comes from him, or from the number of network interfaces up for each tunnel: ppp0, ppp1, ..., pppN

Answer 2

most likely this number is limited by the number of simultaneously open descriptors or files, and this is configured in the kernel parameters