How do I telnet from a esx host?

[serenitynow98]

I am trying to check and see if a port on the license server is open and I need to telnet from an esx host to the license server..

But base install of ESX looks like does not come with a telnet client.

Anyone know how to telnet from an esx host or is there some other way I can check and see if it is able to talk to another server on a particular port?

[serenitynow98]

I guess I should add that I am not able to communicate with the license server from the ESX host.

Can someone tell me what port needs to be enabled/open from the host to the license server and vice versa for licensing to work?

[MR-T]

Telnet will be disabled by default.

You can make firewall changes from the configuration > security section.

For licence communication, the following ports are used:

27000 Licence transactions from ESX server to the licence server Outgoing TCP

27010 Licence transactions from the licence server Incoming TCP

[serenitynow98]

I know that and network team has confirmed the ports are open.

I need someway to verify that..

On a windows server we use telnet but what is its equivalent on ESX?

[MR-T]

You can enable the telnet client, it's on port 23.

From within the VI client, select the configuration tab, then security profile, firewall, properties and browse down to the telnet client item.

[Paul_Lalonde · Accepted solution]

1) Put the ESX CDROM into the server.

2) Type: mount /mnt/cdrom

3) Type: cd /mnt/cdrom/VMware/RPMS

4) Type: rpm -Uvh telnet-0.17-26.EL3.3.i386.rpm

5) Enable the Telnet outbound firewall port

Done!

Paul

[serenitynow98]

Paul;

U R DA MAN.

Thanks ever so much...

Just what i wanted..

[mkats]

You are the man.

[espi3030]

I was late in reading this post, I ssh in between my esx hosts by issuing "esxcfg-firewall -e sshClient" to enable SSH, then "esxcfg-firewall -d sshClient" to disable it. DO you have to use telnet? This is very quick and easy.

[mkats]

I use ssh as well and telnet for network access verification.

[Mr_Flibble1]

I would recommend that you dump telnet entirely if possible. A few strange devices (routers etc) still seem to use it. However, it does present a serious network risk.

I remember using a program back in the day called "hunt" which allowed you to hijack telnet sessions. Never mind the ability to sniff the plaintext. Ah, those were the days.

[mcowger]

Few of you are paying attention to what this user is doing (using telnet to verify TCP open ports) and instead getting all scared about using telnet for management (which he ISN'T doing).

Telnet for this purpose is FINE.

--Matt

[Mr_Flibble1]

Actually, I noticed he was doing that, but in that context I usually use nmap. I just try to avoid using telnet in general, unless on a windows machine where I don't have nmap installed.

[williamarrata]

Coulden't he just NANO etc/services and look at the Telnet service and see it that way?

[Mr_Flibble1]

He could, but mcgower has a good point. You can use telnet to check a remote host for a given service. Such as email or http by: "telnet example.com:25"

[robpomeroy]

Apologies for bumping such an old topic.  I caught sight of it while looking to resolve a similar problem.  I'm using ESXi 5.  Althought there's no telnet client present, netcat is there at /bin/nc - viz:

~ # nc 192.168.1.2 80
GET / HTTP/1.0

HTTP/1.1 403 Forbidden
Date: Fri, 20 Jan 2012 10:42:20 GMT
Server: Apache/2.2.15 (CentOS)
Accept-Ranges: bytes

...