Telnet UDP port

[tankvishal1108]

I want to test connectivity on udp port 500 on other side

how could i check whether udp port 500 is up or not

what command used on cisco router and ASA?

[md.irfan.khans]

You Can use packet tracert in ASA and check the logs on Router 

packet-tracer input [src_int] protocol src_addr src_port dest_addr  dest_port

Ex for ASA :  packet-tracer input ( Interface name ) tcp 10.1.1.1 5067 10.4.1.1 23 

[tankvishal1108]

Basically I am establishing a tunnel between router and firewall

on firewall by default icmp is disable 

i want check end to end  connectivity

how can i check that;

firewall is not under my administration

i have only access to router..

[johnlloyd_13]

hi,

you can't use telnet to test UDP. telnet is used for testing TCP ports only.

you can issue the show crypto ipsec sa if it's a cisco router.

see helpful link:

http://ccnpsecuritywannabe.blogspot.com/2014/08/ikev1-ipsec-site-to-site-vpn.html

871W#show crypto ipsec sa

interface: BVI1
    Crypto map tag: 871_IKEv1_CMAP, local addr 192.168.1.1

   protected vrf: (none)
   local  ident (addr/mask/prot/port): (192.168.1.1/255.255.255.255/0/0)
   remote ident (addr/mask/prot/port): (192.168.1.2/255.255.255.255/0/0)
   current_peer 192.168.1.2 port 500

[tankvishal1108]

Hi thnx for replay 

I know step for establishing tunnel between two point's 

But before establishing tunnel we use to check end to end connectivity. 

as you shared a link

consider i am configuring site-to-site vpn on router

and ASA is other end of tunnel  which shared me the required parameter(and they have opened udp port 500 and 4500)

But before configuring all policy generally we use to check connectivity; whether other end is reachable or not

how will you check if icmp is disable on the firewall  

[johnlloyd_13]

hi,

you can check the ACL and MPF configured on the ASA.