[j-nsp] FW: VPN 3005 concentrator 3DES to Juniper M20 [7:7044 4]

Thu Jun 12 08:56:25 EDT 2003

Hi,

	I had a similar problem to what you're highlighting. My problem was that the M20 didn't support PMTUD for GRE tunnels terminated in VRFs causing a black-hole phenomenon . We had to upgrade to Junos V5.5R3.1 because it was the only release that fixed this problem. After the upgrade we faced another problem with subscribers unable to access some websites. Reason was due to the famous problem of discarding ICMP type 3 code 4 (Fragmentation needed) on the internet on the way back to the webserver (RFC2923). We fixed the problem by adjusting the MSS value in TCP SYN packets to avoid the generation of those ICMP packets. Now, I haven't worked much with IPSec, but I think you can configure a definite MSS value on the concentrator or the client to enforce the endhosts to do all the fragmentation before sending out the packets. 

Hope this helps.

Magdy

-----Original Message-----
From: Julian Eccli [mailto:je at juniper.net]
Sent: Wed, June 11, 2003 7:19 PM
To: Lars Higham; juniper-nsp at puck.nether.net
Subject: RE: [j-nsp] FW: VPN 3005 concentrator 3DES to Juniper M20
[7:70444]

IOS 12.2.13T and above has been tested for interop with JUNOS ES PICs
and works just fine.  I had issues with IOS versions below this.

-Julian

> -----Original Message-----
> From: Lars Higham [mailto:lhigham at yahoo.com]
> Sent: Wednesday, June 11, 2003 6:39 AM
> To: juniper-nsp at puck.nether.net
> Subject: RE: [j-nsp] FW: VPN 3005 concentrator 3DES to Juniper M20
> [7:70444]
> 
> 
> Hello Bosco,
> 
> Cisco's general answer to everything is to upgrade 
> IOS/hardware so your
> customers are probably used to hearing it - particularly when
> implementing new features.
> 
> 
> Regards,
> Lars
> 
> -----Original Message-----
> From: juniper-nsp-bounces at puck.nether.net
> [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Bosco
> Sachanandani
> Sent: Wednesday, June 11, 2003 5:58 PM
> To: juniper-nsp at puck.nether.net
> Subject: RE: [j-nsp] FW: VPN 3005 concentrator 3DES to Juniper M20
> [7:70444]
> 
> 
> Hi Group
> 
> Thanks Lars and Tony for the feedback.
> 
> Just a couple of insights:
> The tunnel status between both the boxes is up ie the IKE as well as
> IPsec part. Infact, when I established connectivity for the first time
> between the two, I was able to telnet and ftp (login only) from a host
> behind the Juniper to a host behind the VPN concentrator. 
> Hence as Lars
> suggested below, I do not think it's got to do anything with IKE/IPSec
> negotiation. Also, there are no firewalls / ACLs defined in between.
> 
> The problem is definitely got to do some thing with resassembly of the
> ESP when it reaches the Juniper ES-PIC.
> 
> Well seems like there is a certain software upgrade possible on the
> Cisco Box, I have to get my hands on that one and test it out 
> first, am
> planning to do so next week.
> 
> What I am seeking help from you guys about is that is there a way of
> re-configuring something on the Juniper or some software patch that
> allows me to configure fragmentation and packet assembly? You see most
> of our customers here are using a Cisco box, I can't keep telling them
> to upgrade to a higher IOS or Concentrator software 
> version...... better
> try and change something from my side.
> 
> Thanks a ton for listening.
> 
> Cheers
> Bosco
> 
> PS: Hey Tony! This Juniper Installation has been done by EPA 
> itselF!! :)
> You can check it up with EPAHAHE..He has pointed out certain 
> things for
> me to do here and check. Cheers!
> 
> 
> -----Original Message-----
> From: Lars Higham [mailto:lhigham at yahoo.com]
> Sent: Tuesday, June 10, 2003 8:07 PM
> To: juniper-nsp at puck.nether.net
> Subject: RE: [j-nsp] FW: VPN 3005 concentrator 3DES to Juniper M20
> [7:70444]
> 
> 
> Hello Bosco,
> 
> First, ping across using small packet sizes, say 256 bytes.  
> If it still
> doesn't work, it won't be an MTU/fragmentation issue.
> 
> Set traceoptions on the Juniper and send us some output - 
> including the
> initial IPSec negotiations, as well as when you're trying to
> send/receive the aforementioned pings.
> 
> 
> Regards,
> Lars Higham
> 
> -----Original Message-----
> From: juniper-nsp-bounces at puck.nether.net
> [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Bosco
> Sachanandani
> Sent: Tuesday, June 10, 2003 3:43 PM
> To: juniper-nsp at puck.nether.net
> Subject: [j-nsp] FW: VPN 3005 concentrator 3DES to Juniper 
> M20 [7:70444]
> 
> 
> I have send this mail to the Cisco group too to get some
> insights.....would appreciate some feedback from you all too!
> 
> TIA
> Bosco
> 
> 
> -----Original Message-----
> From: Bosco Sachanandani 
> Sent: Tuesday, June 10, 2003 2:21 PM
> To: cisco at groupstudy.com
> Subject: VPN 3005 concentrator 3DES to Juniper M20 [7:70444]
> 
> 
> Hey Group
> 
> I have a Cisco 3005 series concentrator box configured to run 
> between my
> Externel router and Checkpoint firewall such that:
> 
> INTERNET Router -------> VPN 3005 --------> Checkpoint------LAN
> 
> This is one segment of my network. On another segment of the network I
> have a Juniper M20 router with an encapsulation card that is connected
> to the internet via a different ISP.
> 
> I have sucessfully established a 3DES IPSec tunnel between these too
> although I must admit that the freakin GUI interface of the VPN3005
> sucks big time and is confusing compared to the ultra cool 
> Juniper CLI.
> It took me a while to explore the damn hidden options in the GUI!
> 
> The problem is that although the tunnel is established, no 
> data can pass
> through it! From what I have heard from a reliable source, 
> there is some
> compatibility issue relating to the frame size and packet 
> fragmentation
> when it arrives at the Juniper Interface. Juniper says that it's
> router's are designed for a high amount of Internet traffic and that
> packet fragmentation is not something a gateway router should be
> bothered about. However, they have suggested certain Cisco boxes like
> the 3662 that allows for packet fragmentation and other such stuff....
> 
> Any of you guys wanna shed some like on this and tell me how 
> I can make
> the 3005 talk to the M20?? Thanks a ton Cheers Bosco
> 
> 
> 
> 
> Message Posted at:
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