Tagged Questions

Internet Protocol Security (IPsec) is a protocol suite for securing Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session. IPsec also includes protocols for establishing mutual authentication between agents at the beginning of the session ...

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3
votes
1answer
27 views

which diffie-hellman group is needed for secure ike/ipsec

We're deploying ipsec on embedded devices and getting catastrophic performance from the diffie hellman 2048 group in ike.. afterwards the shared securet is used for 3des, sha1. ipsec negiation is ...
0
votes
0answers
18 views

Establish IPSEC Tunnel between two Ubuntu 12.04 PCs over LAN [migrated]

I have two ubuntu 12.04 32 Bit PCs between which I want IPSec Tunnel to be setup. I have setup ipsec in both systems and ipsec verify runs fine on both. Since I have no prior experience of openswan, I ...
2
votes
1answer
40 views

Best Practice: frequency to change IPSec pre-shared key

Is there any Best Practice as far as changing IPSec pre-shared keys for security purposes? Obviously, larger companies would have a issue changing these and then pushing the new key out to the user ...
1
vote
0answers
11 views

Can someone help me understand ALG and VPN settings on my router? [migrated]

I'm looking at the settings in my TP-LINK WDR4300 router and noticed settings for VPN passthrough and ALG. Every single option is enabled but I am hoping someone can help me understand these settings ...
-1
votes
0answers
12 views

IKE(v2) with pre-shared publc keys?

Is using IKE(v2) to only talk to a pre-defined set of peers by their Public Keys supported as part of the protocol? As in, for a given peer, can I give that peer a set of 3 public keys P1, P2, P3 and ...
2
votes
1answer
47 views

how IPS and IPSec work together in a host

I want to know how they work together . for example , we implement IPSec tunnel between 2 routers and we establish Snort IPS on Router 1. when Router 1 get the packets , they're encrypted . Now which ...
0
votes
0answers
46 views

Finding the IP address origin of malware attacker behind VPN and proxies

I have a client that wants me to begin doing research on finding the origin of a persistent attacker to their network and employees. I haven't gotten the specifics yet, but I'm trying to think of ways ...
5
votes
0answers
72 views

Maximum number of nodes with IPSec?

From my understanding, for incoming packets over IPSec, the Security Association (SA) is identified by the SPI field of the ESP header. Then let's say I have a bunch of nodes where each node wants to ...
2
votes
1answer
72 views

Does mixing different types of encryption make the connection more secure?

Like when I browse a website using SSL from my laptop that is connected to my router using WPA2. My router talks to my ISP using IPSec. Is that more secure or these types of encryption have nothing ...
2
votes
1answer
89 views

Are all TCP connection protected by IPsec?

I hope this question fits this stackexchange: From what I understand, IPSec takes care of encrypting everything above the IP layer (transport, application). Does that mean that if I open a socket ...
1
vote
4answers
215 views

Are there any reasons for using SSL over IPSec?

is it recommended to use both protocols together? In which situation?
0
votes
0answers
56 views

Key differences between IPSec and HAIPE?

HAIPE is derived off IPSec but can someone draw up the differences between using IPSec with Suite B crypto and HAIPE with Suite B? We can drop Suite A or classified info for this question; staying ...
0
votes
2answers
305 views

Given an IP address can you ssh into /tmp without password?

I'm a Software Engineer, but I have no experience in security, so i'm trying to learn by doing (woot Experiential learning!). I know that the permission settings on the tmp folder are very relaxed. ...
1
vote
1answer
105 views

Practical way to communicate a pre-shared key?

Company A needs to set up an IPsec VPN with company B, where each side will configure its own devices. Is there a recommended practical and quick way to communicate a pre-shared key from A to B? I ...
0
votes
1answer
77 views

IPSec Protocol Sequence Number

On IPSec protocol, how can denial of service (DoS) be prevented or its effect be minimized? For example, assume an attacker intercepts a packet and changes its sequence number to a bogus one (say 10 ...
2
votes
1answer
69 views

IKEv2: Why is it important “that each side sign the other side's nonce”

I am currently diging deep into the IKEv2 protocol. In the description of the Authentication (RFC5996, p. 48), the following statement is given: "It is critical to the security of the exchange that ...
1
vote
1answer
517 views

Understanding the details of SPI in IKE and IPsec

I'm currently learning IKE and IPsec for an exam. I have a lot of information on how Security Parameter Indexes (SPI) are used in both protocols, but I'm having some problems figuring out the ...
1
vote
0answers
133 views

Does using NAT-T for L2TP / IPsec VPN pose a realistic security risk?

I'm working on upgrading an old Windows RAS server that hosts PPTP VPN. I want to move to a L2TP/IPsec VPN. Due to the firewall appliance we use, the VPN server has to be behind a NAT. This means ...
1
vote
2answers
57 views

is IPSEC Authentication between local domain hosts a part of normal behaviour in a Windows network?

I am seeing lot of IPSEC Authentication messages in eventlogs of Windows domain hosts. I was wondering if this - setting up IPSEC connections between domain workstations is a part of normal Windows ...
2
votes
1answer
206 views

PFS incentive during IKE Phase 2

I'm trying to see the actual point in implementing Perfect Forward Secrecy during Internet Key Exchange Phase 2, if it had already been used during Phase 1. Quoting the IKEv2 RFC: RFC 5596 ...
2
votes
1answer
107 views

IPSec sequence number

I was going through a study of IPsec and I found that there are redundant sequence numbers: one in the AH or ESP header, and the other is in the TCP header for a communication. Is it not an ...
1
vote
1answer
304 views

How should IPSec be configured to provide a protection at least as good as my current Stunnel configuration?

In private network (as in using a private IP address space) at a cloud provider, other customers have access to the same private network. I have secured the communication between many hosts and ...
1
vote
1answer
46 views

Is it possible to use AH in transport mode on an IPSec channel with mediation?

I understand that it's not possible to have Autentication Header with a regular NAT, because it messes with the IP header protected by AH. How about proxies? Do they change anything in the packet? ...
1
vote
1answer
107 views

IPSec optional advanced questions [homework] AH/ESP and Tunnel/Transport modes

I have 2 questions regarding IPSec. This is the last 2 optional questions of my homework: Scenario when combining AH and ESP can be needed? Scenario when combining Tunnel and Transport modes can be ...
2
votes
2answers
240 views

Skype Audio / Video Session over VPN?

Basically I'm wondering if a Skype video session along with audio could be logged (or recorded) over a virtual private network? I know whoever hosts the VPN server can log which websites you visit (or ...
1
vote
2answers
181 views

Is QuickVPN Secure

Does QuickVPN create a secure tunnel or how does it work to provide encryption and security? When I did a see my IP it was using the remote locations IP and not my office network's IP so does that ...
0
votes
1answer
173 views

NAT traversal for IPsec AH protocol

Wherever I looked I only saw the description of NAT traversal for ESP protocol (for example: http://pic.dhe.ibm.com/infocenter/iseries/v6r1m0/index.jsp?topic=/rzaja/rzajaudpencap.htm) It's looks that ...
1
vote
1answer
446 views

How does IPSec protect against IP spoofing?

IPsec is a security mechanism that provides peer-entity authentication, data-origin authentication, data integrity, and optionally data con´Čüdentiality. It relies on extensions to the standard IP ...
2
votes
2answers
1k views

How to detect NAT - network address translation?

How to detect if NAT is used in network or not ? I know if you have private address and you are able to connect public network or internet then there must be NAT. But How can I detect that NAT is ...
0
votes
1answer
175 views

how can I secure my static ip router?

hi I have a static ip and someone is hacking my computer trought it I tried to format my computer and making a clean install but he keeps penetrating it this time i tried to install the AV before ...
1
vote
1answer
109 views

Using secp256k1 and ECDSA with IKE

I just tried using an IKE daemon and EC certificates. I used the secp256k1 curve for key generation. The daemon claims signature scheme ECDSA-256 not supported by private key Now I am wondering ...
3
votes
2answers
2k views

What is the difference between SSH and IPsec?

There seems to be similar encryption going into both. They both use asymmetric (RSA, elliptic curves, etc) for the initial key exchange, then go to some symmetric (AES, Blowfish, etc) protocol. I'm ...
4
votes
2answers
3k views

Which is better for server-to-server-communication: IPSec or TLS?

Maybe you could help me with a small problem. Would you recommend IPSec or TLS for a Server-to-Server-Connection? I need two or three arguments for reasoning a decision within my final paper, but ...
1
vote
1answer
249 views

Is it necessary to use PEAP for L2TP/IPsec?

This is a sister question of Is EAP-MSCHAP v2 secure?. Based on my understanding, IPsec should have authenticated the server (we're using PKI) and secured the rest of the protocols before the user ...
1
vote
1answer
328 views

How to authenticate to racoon with a certificate chain if only the root CA is known

I'm trying to setup IPsec using x509 certificates on Linux. I'm using racoon for that task. I've come to the point where the authentication works fine if I keep every link of the certificate chain on ...
2
votes
2answers
2k views

IPsec using pre-shared keys

I am trying to understand why do we really use those pre-shared keys when creating a IPSec tunnel. From all the reading that I have done the DH group creates the keys that are used to do the actual ...
2
votes
2answers
650 views

Strongswan crypto

How does StrongSwan enable different crypto libraries?
-1
votes
1answer
97 views

Where else is IPSec used, besides with VPNs? [closed]

IPSec is most commonly used to secure VPN traffic. Where else is this protocol suite used? What else can it be used for?
6
votes
4answers
3k views

Does IPSec use IKE or ISAKMP?

Does the IPSec protocol suite use IKE or ISAKMP? RFC 2828 states ISAKMP is the protocol used in IPSec to handle SAs, key management and system authentication. Other sources say IKE is the protocol ...
1
vote
1answer
114 views

IPSec, hubs, crypto maps

I thought hubs were layer 1 devices, and so would have no active role in IPSec. I am reading to understand crypto maps, Dynamic crypto map policies are used in site-to-site VPNs when an unknown ...
2
votes
3answers
688 views

Filtering In Iran

Since many of you already know the Iranian government aggressively uses internet censorship to block sites such as facebook, flicker, bbc, etc. The Iranian people use various methods to bypass ...
2
votes
1answer
276 views

what is a security association and how does it relate to ipsec?

I am learning IPSec. My class notes define a security association as a one way relationship between sender and receiver that (1) affords security for traffic flow and (2) is identified by the ...
5
votes
2answers
1k views

Encryption of headers in IPsec tunnel mode

I am learning about IPsec's transport and tunnel modes. I understand that transport mode encrypts only the payload of an IP packet and is used for communication between two entities that both ...
2
votes
1answer
869 views

IPSec AH + ESP used together

When ESP and AH are used together (ESP transport, AH transport) on the same packet does ESP encrypt the AH's hash, or is the hash left in the clear? If the hash isn't encrypted, there are obviously ...
5
votes
1answer
1k views

How do I make or get computer certificates to use with IPSEC user authentication on Windows?

I am having trouble and need some direction using computer certificates with Windows 7 firewall IP Security rules, using certificates only for user authentication. I can get everything to work ...
2
votes
1answer
245 views

Normalizing Windows Advanced Firewall rules

How can I best normalize our Windows Advanced Firewall rules while implementing network segmentation? I want them to be as clear and concise as possible for audit purposes. What few examples I've seen ...
4
votes
3answers
205 views

How can an outsider tap into communications between two physical sites?

When referring to 'Sites' - I am not talking about a website, but of a physical place where a company resides. Today, to secure communications between two sites - Let's say between an office in ...
-2
votes
2answers
597 views

What software can I used to edit and replay packets? [closed]

From the Wikipedia article on anti-replay: The main goal of anti-replay is to avoid hackers injecting or making changes in packets that travel from a source to a destination. Is this commonly ...
1
vote
4answers
1k views

IPSec VPNs and symmetric keys

When dealing with IPSec based VPNs, I understand that there is a slight "problem" with symmetric key exchange. Obviously, you can't send the keys over the VPN, since they are used to guarantee the ...
5
votes
1answer
817 views

IPSec Domain Isolation with Windows Server

I'm looking for a good way to secure my servers, I have a set of dedicated servers that are not in my office but hosted by an external provider. ALL the servers have only one public (WAN) IP. I don't ...