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Questions tagged [ipsec]

Questions relating to IPSEC VPN configuration, operation and troubleshooting specifically.

1
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0answers
31 views

GRE over IPsec problem

I'm trying to build a GRE Tunnel with IPSec encryption between two routers, but I keep getting error message saying "%CRYPTO-4-RECVD_PKT_NOT_IPSEC: Rec'd packet not an IPSEC packet..." Immediately I ...
0
votes
0answers
14 views

does ipsec phase1 renewal keep connections?

I have an IPSec tunnel UP and I open a TCP connection when the phase1 expire and is renewed, Is the TCP connection supposed to stay alive or drop ? both in the theory and practical (cisco, ...
6
votes
2answers
4k views

How to configure Cisco remote access IPSEC VPN between IOS Router and Android phone

I have a C891FW router with IOS 15.4 on which I'm trying to configure a remote access VPN for Android's native VPN client. I'm authenticating with RSA-Sig and XAUTH. The tunnel forms but I can't reach ...
1
vote
1answer
42 views

VoIP, IPsec configuration

I have a topology in GNS3 with an IPsec VPN tunnel between C1 and C2 (https://imgur.com/dnNkssU). In clients networks i am configured a CME and a Softphone. When i make a call the quality is very bad. ...
0
votes
1answer
25 views

Can both IPsec endpoint be configured as the initiator?

Then configuring an IPsec tunnel, I can usually set if the device should act as the initiator or the responder (or even both). However, what would happen if both endpoint are configured as the ...
2
votes
2answers
8k views

Cisco ASA: Unable to establish IPSec tunnel with IKEv2: Auth exchange failed

This is a Cisco ASA 5515-X with software 9.6(3)20. The remote side didn't tell me what they use, must be Strongswan or something. Using the following debug commands debug crypto ipsec 255 debug ...
2
votes
1answer
2k views

IPSec IKEv2 connection failure due to RSA authentication issue

I'm trying to get an IPSec/IKEv2 setup working, which was implement following this I don't understand why, but when a client connects (StrongSwan on Android here), the session is closed because the ...
3
votes
3answers
12k views

rec'd IPSEC packet has invalid spi

I have setup a lab to play with DMVPN and EIGRP. Everything works perfectly fine until I test things by shutting down redundant ports. Once I do that the DMVPNs never recover even after restoring all ...
3
votes
0answers
67 views

IPSec Tunnel not coming up: Issue with ACL?

I'm trying to bring up a IPsec tunnel between router and a bridge. I can see the Ipsec tunnel configurations are up and running but I think I have made a mistake in the ACL and hence the encr and decr ...
3
votes
1answer
98 views

Pass traffic from remote access to site to site tunnel

I have situation where remote access ipsec client have to connect to ASA firewall to send and receive traffic using site to site tunnel on the same ASA, in the logs I am seeing packets dropped as it ...
2
votes
1answer
49 views

MAC Address not resolving when IPSec VPN in place

I've created an IPSec VPN connection between two Mikrotik routers. They are connecting via IKEv2. Inside our two networks, we have a printer spooler which needs the printer's MAC address to verify it'...
2
votes
1answer
53 views

High Availability for ISR 4431 IPSec VPNs

I have the following lab setup in GNS3. R1 & R2 are VPN endpoint at my datacenters and R3 is simulating a remote site. What i'm trying to accomplish is having one tunnel from R3 to the ...
1
vote
1answer
109 views

Keep Cisco site-to-site tunnel up permanently

I have Cisco ASA site-to-site tunnel with remote and which i don't have control. I have following config: crypto ikev1 policy 10 authentication pre-share encryption aes hash sha group 2 ...
3
votes
1answer
58 views

Traffic not send in IPsec with a Cisco ASA

I try to set up a site to site IPsec between an Ericsson router and a Cisco ASA, as shown below: My tunnel is UP and R1 seems to be working fine. However, my ASA does not forward traffic between ...
3
votes
3answers
5k views

How to check if IPSec is available on Cisco ISR 4451

On a Cisco isr 4451 with base image I need to check if IPSec is available. Is there an command to list available vpn features? UPDATE The image name includes K9 (UNIVERSALK9-M) but the command failed ...
1
vote
1answer
50 views

IPSec route-based vpn st0 interface

As i know, the st0 interface is used when the gateways are configured with route based VPN. But my question is, say below is the topology A<---->B<---->C<---->D A and D are hosts, B and C ...
0
votes
1answer
33 views

What is the reason for encrypting Identity field under IPsec phase1?

Why Identity fields are encrypted in IPsec phase 1 around packet 5/6 ? provided that the Identity field contains IP of either end. Does it has any significance ? Does it holds anything different then ...
0
votes
0answers
53 views

ASA - communication between 2 tunnels

I have two IPSEC tunnels with an ASA in the middle Site A - 10.20.4.0 /24 (65.176.80.84) Site B - 192.168.142.0 /24 ASA - 10.99.206.0 /24 (95.12.22.33 Site A - 10.20.4.0 /24 can reach the ASA and ...
-2
votes
1answer
50 views

IPSec SA being Unidirectional

From what I’ve read, IKE SAs are Birectional and IPSec SAs are unidirectional. But if the same proposals are to be agreed by both the ends, say protocol esp, Authentication algorithm as hmac-sha1-...
0
votes
0answers
38 views

IPSec Tunnel is up but no Communication with End Systems?

I need help for IPSec tunnel. Currently, I am working on a small task to create remote access between my laptop and office router, in order to access the office LAN network. IPSec tunnel is working ...
1
vote
1answer
57 views

IPSec tunnel between 2 LANs using HSRP in each side

This is my first post here, so tell me if there's something I'm doing wrong. I'm currently working with another IT student on our end of degree project and we're building our network in PT. Our ...
3
votes
1answer
193 views

How IPsec tunnel mode work without GRE

IPsec tunnel mode encrypt a whole IP packet and sends it as the payload of another IP packet. I have always used GRE as the encapsulation layer when doing IPsec encryption. However, how could I have ...
0
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0answers
63 views

Query on Cisco IPsec Licensing, HSEC-K9

I'm currently debugging an issue with IPsec tunnels and it seems like one of our client's NW engineers didn't install the HSEC-K9 license. The issue is that the new IPsec tunnels are not coming up ...
1
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0answers
64 views

Why do the tunnel protocol on these two router show different values

Two routers R1 and R2 have a tunnel built between them in the 103.103.103.0/24 network. The end point of the tunnel are 75.75.75.2(on R1) and 76.76.76.2(on R2). Can anyone explain why does the Tunnel ...
1
vote
1answer
28 views

Can a VPN tunnel between routers be built with different tunnel protocol on both ends?

I have two routers and the tunnel between them is up and working well. Router1 has GRE/IP as the protocol on its tunnel interface, and as for Router2 the tunnel interface is working with IPSEC/IP. Can ...
3
votes
1answer
162 views

Azure VPN vs. Cisco ASA

I have a Cisco 5516-x with v9.7(1)21 on my end and I am trying to create a working VPN to Azure. It looks to me like phase1 goes well but phase2 fails due to policy mismatch. Any suggestions for how ...
2
votes
1answer
39 views

Why aren't we encrypting data on Network level instead of transport level when using e.g. HTTP [closed]

Why we are bothering to encrypt our data on a transport level, instead of just doing that on a network level with e.g. IPSec and get rid of the need to to that in upper layers. For example instead of ...
0
votes
1answer
56 views

Can I use the same IPsec tunnel for two VRF?

I have two routers linked by two logical links in two different VRF. I should move one router to another site and use Internet to keep the same connectivity. Since I use private IP addresses in my VRF,...
1
vote
2answers
64 views

AWS site-to-site VPN and multiple account VPC connections

I've configured a site-to-site VPN from our firewall (watchguard) to AWS. Now, how can I connect Account A with Account B? I've already an OpenVPN server in account A to which account B connects (...
0
votes
1answer
576 views

WatchGuard Mobile VPN with IPSec - “The VPN server did not respond”

I have been following official WatchGuard guide (mvpn_ipsec_ios_vpn_c.html) to set up Mobile VPN with IPSec on WatchGuard Firebox x750e v10.2.12. Inside the Policy manager, I can see this has been ...
4
votes
1answer
188 views

Use cases for GRE over IPSEC

I'm trying to understand use cases for GRE over IPSEC. In the diagram below, each site uses GRE to encapsulate multicasts associated with OSPF. (There is still a requirement to configure SAs between ...
3
votes
2answers
467 views

IKE phase 1 and phase 2

Was going through the IKE phase 1 and phase 2. I have some questions regarding the same which is bothering me with respect to main mode and quick mode.Please correct me if i go wrong somewhere. Phase ...
1
vote
0answers
145 views

AWS tunnel TCP retransmissions and DUP ACKs

I have a IPsec tunnel from my firewall towards AWS, the tunnel is up in both phases. If I run traffic sniffer in the firewall, I can see interesting traffic going through, but there are MANY TCP ...
1
vote
1answer
41 views

Shared secret key for Diffie-Hellman key exchange

From what i have learnt,in Asymmetric key there is public key and a private key. For instance: Step 1: Alice and Bob get public numbers P = 23, G = 9 Step 2: Alice selected a private key a = 4 and ...
1
vote
1answer
80 views

Outbound NAT for single host behind an ASA located over an IPSEC tunnel [closed]

I have these two nets connected over the public internet with ASA 5510s. 192.168.0.0 < -- ASA1 ---> Internet <--- ASA2 --> 192.168.5.0 Each net does either a simple dynamic or static nat ...
3
votes
1answer
2k views

IPsec Tunnel is showing decrypt packets counter but 0 encryption packets: #pkts encaps: 0, #pkts encrypt: 0, #pkts digest: 0

I have just configured the IPSEC tunnel between my router and the Access point.I could see that the Tunnel has came up and Active in both sides. However,When I checked the "Show cyrpto ipsec sa" ,I ...
1
vote
0answers
411 views

ipsec tunnel between Cisco IOS router and Perle IOLAN SCS 32

I cannot get a IPsec tunnel up and run between a Perle IOLAN SCS 32 with firmware 4.5 and Cisco ASR 1001 with IOS XE 15.3 - it fails in phase 2 with invalid proposals Has some out there a sample for ...
1
vote
1answer
426 views

ASA VPN Tunnel NAT Issues

I've been trying to jump through two tunnel. A Customer has a cloud solution which we need access to. Since we already have a vpn site2site tunnel to the customer we can already access his LAN. What ...
2
votes
1answer
464 views

L2TP IPSec Remote VPN - Many users connecting remotely from same access

Can someone explain to me, why isn't possible to connect 2 or more clients to a VPN server when the users are behind the same public IP (NAT/PAT). What I mean is: if there is already a user connected ...
2
votes
1answer
161 views

how security association (SA) is established?

I'm a newbie in networking, still struggling to understand some concepts. I was reading a text describes security association (SA) in VPN. Whenever router R1 needs to construct an IPsec datagram for ...
1
vote
2answers
3k views

IPSec in IPv4 and IPv6

I'm getting a little confused in understanding the differences in IPSec in IPv4 and IPv6... Are the principles of IPsec the same in v6, but instead of it being optional it is now mandatory for it to ...
2
votes
1answer
287 views

Junos IPSEC Tunnel to Azure & TCP-MSS

I am configuring a Juniper SRX 300 Series to establish an IPSEC tunnel to Azure. The Azure Vnet range is 192.168.10.0/23 The local range is 10.49.236.0/24. The configuration: (relevant bits with ...
1
vote
1answer
419 views

Result of running `restart ipsec-key-management`

I have Juniper SRX 1400 which is used mainly for IPSEC tunnels. And now I facing a bug in firmware with ID PR1085657 (IKE doesn't come up when the SRX is the initiator). Possible solutions to this is ...
2
votes
1answer
550 views

Site-to-site IPSEC for multiple peers with dynamic IP on Juniper SRX

Looking for possible solution. I have Juniper SRX 1400 (12.1X47-D20.7) with static WAN IP in data-center and multiple sites with dynamic WAN IP addresses. I need to build with them site-to-site VPN's....
2
votes
0answers
323 views

RSA key not working with trustpoint used for IPSec

I'am trying to setup an IPsec IKEv2 tunnel where the local authentication mechanism is based on RSA. Therefore I have setup a trustpoint and I got a signed certificate for this setup. Importing is ...
2
votes
1answer
128 views

Latency-sensitive channel bonding

One of our satellite offices is connected by a Satellite connection with no other high bandwidth option. Reliability is good and bandwidth is acceptable (50/10 MB/s), but latency is making, ssh, VPN ...
2
votes
2answers
726 views

GRE-IPsec Tunnel between Cisco Router and a Linux Router

I am trying to create a GRE/IPsec tunnel between Cisco router and a Linux Router. The tunnel is UP and active, but when I do a "show crypto session" on the Cisco router the Active SA's keep on ...
1
vote
1answer
630 views

DSCP trust over IPSec GRE

I have 2 branch offices connecting together via a metro-e and I'm running an ipsec gre tunnel between the 2 sites. routerA=branch1 routerB=branch2 WAN-------routerA----------|metroe|------------...
4
votes
1answer
3k views

IPSec failure with `IKE message failed its sanity check or is malformed`

I've been battling with my IPSec configuration for some days (with foolish deadline looming) and would like to ask for help with it failing its initial connection. It's designed as client-to-router ...
2
votes
0answers
31 views

encryption gateway vs domain and source ip issues [closed]

(This is the same setup as a previous question.) My VPN connection was no longer working (for ~4h), so I called the remote end's tech support. While we were talking, the link mysteriously started ...