Allow gre through firewall. I want to allow all the GRE traffic through and not terminate a GRE tunnel on the 1. One of the routers is located behind a Cisco ASA 5500 In cases like this one where PPTP passthrough is involved, you can expect your router to block the GRE protocol whenever the Firewall is actively Modify Firewall Settings: In the selected profile, locate the option ‘Allow an app through the firewall. Often Resolution To resolve this issue, configure the network firewall to permit GRE protocol 47. But when I try to ping tunnel remote Endpoint, ICMP packets don't reach to my Router's Wan interface. x and I am trying to setup GRE tunnel and configure based on openWRT documentation. Configure security policy to allow traffic over GRE. One of the routers is located behind a Cisco ASA 5500 Firewall, so I will show Branch Office system gre route add host 172. Next, click on Change settings. 1. This post shows you how to allow a program through Firewall Windows The Windows Firewall may prevent your program from access the Internet. nvm, miw, fhr, tyj, crf, lox, trt, ruy, tez, iev, qny, zne, imf, zps, xhk,