Questions tagged [tunnel]
For questions about network tunnels.
157 questions
3 votes
1 answer
76 views
Did ipv6 ever solve the issue of opening listening ports at CPE or beyond a carrier-grade NAT router that is not owned or controlled by the user?
Stupid question I know. I guess I'll just stick with ipv4 for another 20 years and not bother with ipv6. But..... Let's say your dual stack net connection does not come with a public IP so to speak. ...
- 141
1 vote
1 answer
105 views
MTU - proactively setting to lower than 1500 on endpoints to prevent tunnel issues
With machines being deployed to various locations where internet is controlled by others, sometimes there can be one or two tunnels which necessitates using lower MTU to avoid communication issues, ...
- 133
1 vote
1 answer
151 views
Inner header and Outer header in tunnel packet
What should be at Inner header and Outer header in tunnel packet ? And then we have tunnel IP address(for both router), tunnel source IP address, tunnel destination IP address. In my understanding, ...
- 165
0 votes
1 answer
873 views
How to remote access CCTV's device behind CGNAT for IPv4, and device doesn't have support for DDNS IPv6? [closed]
TL;DR Multiple locations with local CCTV. How to remote access all of them, with an ISP that services IPv4 behind CGNAT and the DVR doesn't supports DDNS for IPv6. DVR also offers API, SDK, P2P and ...
- 103
1 vote
2 answers
625 views
what is the purpose of GRE in UDP encapsulation if its unidirectional
I was going through this feature of GRE called GRE-in-UDP encapsulation. The RFC says it is unidirectional and the tunnel traffic is not expected to be returned back to the UDP source port values used ...
- 113
0 votes
1 answer
507 views
VXLAN VNI VLAN mapping
Is VXLAN tunneling similar to Q-in-Q tunneling (except VxLAN works at Layer 3), such that each customer/tenant gets its own VNI and each VNI can then map to multiple VLANs, so a single VNI can ...
- 115
0 votes
1 answer
112 views
On what basis does a router actually install GRE headers and remove them?
I am learning about networks and I have reached the topic of tunnels. At the same time, I have a need to set up a GRE (Generic Routing Encapsulation) tunnel between a remote server (to route addresses ...
0 votes
1 answer
137 views
IPSec over L2GRE scenario
I wanted to know if this is a valid scenario and if it is possible to implement. There is a remote site A. and a Data center site B. Both A and B have a edge router which runs an IPSec tunnel. An ...
- 113
0 votes
1 answer
56 views
Which technologies are most relevant for mobile broadband ISP bonding? [closed]
If I have edge router and core router (kind of Hub) and few ISP lines between them what are the most relevant technologies to be used for mobile broadband bonding? Expected result is: if one of ISP ...
- 101
0 votes
1 answer
579 views
DH groups support for isakmp policy
When configuring a site-to-site VPN tunnel between the ASA and Cisco router, I have queries around the ISAKMP policy. As per Cisco documentation for ASA, the crypto isakmp policy groups available are ...
- 67
0 votes
2 answers
639 views
IPsec PFS Confusion
I'm reading conflicting things about how PFS works in IPsec. Some sources say it's simply a renegotiation of the Phase 1 IKE/ISAKMP SA that ignores the original IKE/ISAKMP SA lifetime value and that ...
- 1
0 votes
1 answer
550 views
Can you sniff network traffic through a VPN tunnel? [closed]
Background: I am doing research for building an automated penetration testing application. All tests will be run from some server with a public IP ("testing server"). The objective is to ...
- 3
0 votes
2 answers
2k views
GRE tunnel bridging and MTU mismatch
Background My workplace has 2 office areas which is only 200 meters away from each other. They have their own local networks, their own Internet connections, with routers configured to fallback to the ...
- 453
0 votes
2 answers
2k views
Why does recursive routing happen?
According to: https://study-ccnp.com/gre-tunnels-recursive-routing-problems/ Recursive routing occurs when the router learns the destination IP address for the tunnel interface through the tunnel ...
- 1,770
0 votes
2 answers
1k views
Override tunnel-all VPN connection to print locally
We have a remote office with several users. The users connect to the cable modem there and individually VPN to our NSA2650 via Sonicwall Global VPN client. This client is set to tunnel-all mode ...
