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Questions tagged [gre]

Generic Routing Encapsulation (GRE) is a tunneling protocol, developed by Cisco.

Generic Routing Encapsulation (GRE) is a tunneling protocol, developed by Cisco.

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L2TPv3 tunnel private IPs not working

I'm trying to setup L2TPv3 tunnel between 2 servers - CentOS 7 and Ubuntu 16 On CentOS 7 end I have the following: ip l2tp add tunnel tunnel_id 6000 peer_tunnel_id 5000 encap udp local LOCAL_IP remote REMOTE_IP udp_sport 5002 udp_dport 6002 ip l2tp…
Economist
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IPSEC over GRE tunnel on PFSENSE

I have two PFsense routers xxx.xxx.xxx.28 and xxx.xxx.xxx.27 and local networks behind them 192.168.110.0/24 and 192.168.111.0/24. The point is to set up GRE tunnel with IPSEC between these networks. Actually, the tunnel is already…
Дьяус
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PPTP Passthrough Centos 7/Firewalld router to Windows Server

I have a Centos 7 server running firewalld to allow public services to access internal services on a separate VLAN (dual NICs). I imported a Windows VM but I do not know what rules I need to put in place to allow GRE through firewalld, other than…
Sam Alsalem
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Proxmox NAT with GRE tunnel as outside interface

End goal (ASCII Diagram) WAN->Router->Server->GRE Tunnel->VM network->VM #1, etc. I should explain some things first. I have a server running Proxmox (Debian 8.7 x64). It's connection to the internet is eth0 (behind NAT with GRE protocol forwarded)…
jtl999
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Why am i receiving so many unsolicited GRE packets?

My (linux) server has some fairly simple iptables rules. iptables -A INPUT -p icmp -j ACCEPT iptables -A INPUT -m state --state ESTABLISHED -j ACCEPT iptables -A INPUT -m tcp -p tcp --dport ssh -j ACCEPT iptables -A INPUT -m tcp -p tcp --dport https…
anx
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Reverse proxy for DoS / DDoS protection

after i search how to protect my website host server using GRE tunnels, some friends of this forum give me a tip to use Reverse Proxy that would be better. But i don't found any guide on how to Reverse Proxy, many guides teach only install Nginxs…
rodrigo286
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Load balancing between two (or more) GRE tunnels

I have a hosted service (think zScaler™) that is having me send my traffic to it via GRE tunnels. I am given two appliances and want to load balance my traffic between the two tunnels. I could always statically carve out the network but I would…
TheAdmin8978234
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Ethernet over GRE bridging - Proxmox

I'm trying to install two proxmox on Online.net server's, and I just realized that their RPN feature doesn't work at all like the OVH vRacks. Since I need the different VM's on both hypervisors to be able to talk, I want to set up a tunnel (their…
Ulrar
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Cisco 1941 EIGRP UP DOWN

We have two cisco routers 1841 and 1941. The 1841 keeps generating "holding time expired" and "interface goodbye recieved" about its neighbor the 1941. The VPN IPSec protocol seems to stay up. Unfortuanately the offinding router does not have…
user2506891
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internet access for system over multiple hops of ipsec using GRE and OSPF

I have the following setup: linux client @ 172.16.10.68 linux gateway @ 172.16.10.69, ipsec tunnel to aws box #1, gre tunnel 10.254.0.0/30 aws box #1, ipsec tunnel from linux gw, ipsec tunnel to aws box #2, gre tunnel 1 10.254.0.0/30 and second gre…
user1608061
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GRE - overlay network

I am renting a set of dedicated servers, and they only have a single interface to internet. However, for a lot of use cases, I would like my servers to communicate through a private IP network. For instance, that would allow me to expose internal…
NewbiZ
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IP Tables forwarding tun0 over gre1 (OpenVPN)

I haven't found a very descriptive thread (and sorry if there is one in existence - in my several hours of searching I've found nothing to my specific situation). My main issue here is getting my traffic from tun0 (my OpenVPN server) over to gre1…
Chuck McGoff
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Using my IPs on OVH server via GRE

I can't route my IPs into a OVH server, can you help me to find the problem? Mikrotik GRE IP: 192.168.55.10 OVH Server GRE IP: 192.168.55.20 GRE iface name: ali1_fr1-ovz1 IP to route from Mikrotik to OVH Server: 185.47.128.50 (I want use this IP in…
jmginer
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WCCP and Squid, and Tunnels

I'm trying to configure WCCP + Squid with the following documentation: http://www.crypt.gen.nz/papers/cisco_squid_wccp.html I have a cisco switch, a test client, and a squid proxy server. I think the switch is configured correctly, as I'm seeing…
blindsnowmobile
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How to troubleshoot GRE tunnel issues?

I commonly run into issues where a GRE tunnel (CentOS server to server, not router based) works and pings fine from both ends but the IP / Range being tunneled does not function. This almost always turns out to be some routing issue at the tunnel…
linux911
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