PIX 506e problem with smtp

[soulofmischief]

im having a problem with sending mail from any workstation on my network.our email is hosted off site. it will eventually be sent out but it takes an inordinate amount of time (anywhere from 2 minutes to a day, on a 1600/600kbps conn) for a normal email w/o any attachments.

network<->pix 506e<->soho 71

the soho is just running pppoe.

if i try to telnet(from a workstation on the network) to the email server port 25, it basically just hangs. no connection refused or anything. eventually it will connect.
if i try to do it from the soho 71, it connects instantly.

i added access-list outside_access_in permit ip any any, and access-list outside_access_in permit tcp any any (as a last ditch effort,after trying many other things)at the config prompt of the pix, exited from the config prompt, wr mem. exit from the cmd line.

try my email real quick. same problem, extremely slow outbound. so out of curiousity, i hit dsl reports and grc for some port scans. bothe sites report that everything is filtered, they cant see them.

all outbound traffic is allowed

config as follows:

PIX Version 6.1(4)
nameif ethernet0 outside security0
nameif ethernet1 inside security100
enable password
passwd
hostname
domain-name bbs.local
fixup protocol ftp 21
fixup protocol http 80
fixup protocol h323 1720
fixup protocol rsh 514
fixup protocol rtsp 554
fixup protocol smtp 25
fixup protocol sqlnet 1521
fixup protocol sip 5060
fixup protocol skinny 2000
names
access-list 101 permit ip 192.168.0.0 255.255.255.0 192.168.1.0 255.255.255.0
pager lines 24
interface ethernet0 auto
interface ethernet1 auto
icmp permit any outside
icmp permit any inside
mtu outside 1500
mtu inside 1500
ip address outside x.x.x.x x.x.x.x
ip address inside 192.168.0.5 255.255.255.0
ip audit info action alarm
ip audit attack action alarm
ip local pool vpnpool 192.168.1.1-192.168.1.10
pdm location 192.168.0.1 255.255.255.255 inside
pdm location 192.168.0.43 255.255.255.255 inside
pdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 0 access-list 101
nat (inside) 1 0.0.0.0 0.0.0.0 0 0
access-group outside_access_in in interface outside
route outside 0.0.0.0 0.0.0.0 x.x.x.x 1
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h323 0:05:00 si
p 0:30:00 sip_media 0:02:00
timeout uauth 0:05:00 absolute
aaa-server TACACS+ protocol tacacs+
aaa-server RADIUS protocol radius
http server enable
http 192.168.0.1 255.255.255.255 inside
http 192.168.0.45 255.255.255.255 inside
no snmp-server location
no snmp-server contact
snmp-server community public
no snmp-server enable traps
floodguard enable
sysopt connection permit-ipsec
no sysopt route dnat
crypto ipsec transform-set myset esp-des esp-md5-hmac
crypto dynamic-map dynmap 10 set transform-set myset
crypto map mymap 10 ipsec-isakmp dynamic dynmap
crypto map mymap interface outside
isakmp enable outside
isakmp identity address
isakmp policy 10 authentication pre-share
isakmp policy 10 encryption des
isakmp policy 10 hash md5
isakmp policy 10 group 2
isakmp policy 10 lifetime 86400
telnet 192.168.0.1 255.255.255.255 inside
telnet 192.168.0.45 255.255.255.255 inside
telnet timeout 5
ssh timeout 5
terminal width 80

 

[azstyx]

HI, maybe you are having an IDENT issue, the mail server may be issuing an IDENT and the pix is dropping the request.
Try configuring:
#service resetinbound

 

[soulofmischief]

thanks for the help azstyx.

tried service resetinbound, and tried using the established cmd w/ permitto tcp 113, but i still have the problem.

after i enter in a entry to the config, i exit and then wr mem. if i show config, i see my new rule, but its like its not taking effect (kinda like access-list outside_access_in permit ip any any, and access-list outside_access_in permit tcp any any should open up my pix completely, but when i do a port scan... every port is reported as stealthed/not found).

do i need to use the reload cmd to have these take effect?

thanks again

 

[cchipman]

have you tried removing the &quot;fixup smtp&quot;?

That can often cause problems.

 

[soulofmischief]

no fixup protocol smtp

tried it earlier, no go.

although, i havent tried service resetinbound w/ no fixup.

been mostly trying one thing at a time to see if i can get it to go.

thanks tho

 

[yizhar]

HI.

The mail server is probably trying a &quot;DNS reverse lookup&quot; on your global ip address, and failing.
If you have a fixed ip address, ask your ISP to create a DNS PTR record for it.

http://www.cisco.com/warp/public/110/21.html

Did you try to connect to a different SMTP server? What were the results?
Try contacting the mail server administrator(s). What did they say about the issue?



Yizhar Hurwitz

http://come.to/yizhar

http://teachers.sivan.co.il/yizhar

 

[soulofmischief]

this really getting to me.....

heres what i just did:
# config t
access-list outside_access_in permit tcp any host x.x.x.x eq 25
(all on one line)

(config)# exit

# wr mem (wait till done, checksum is fine)

# reload
confirmed

now if i do that, it should open port 25 to any incoming traffic, right?

well, all port scans are reporting that they cant find port 25....

what am i missing here?

 

[davarg]

just a suggestion, if you haven't tried it already ...
did u apply the access-list to an interface like below

access-group outside_access_in in interface outside

then check to see if you get hits on your counter

 

[davarg]

Sorry about the previous post. I blew right past your access-group statement. Let me offer a different solution. if your mail server is on your inside network, try using static statements for access from the outside. I.e. if your mail server on inside is 192.168.0.122 port 25 try something like this

static (inside,outside) tcp x.x.x.x 25 192.168.0.122 25 netmask 255.255.255.255

(with x.x.x.x as your outside ip and make sure you still have your access-list outside_...)

access-list outside_access_in permit tcp any host x.x.x.x eq 25

davarg

 

[soulofmischief]

davarg, mail server is external (for now). thanks for the info tho. im probably gonna be moving it to here in next week or two.

i should be able to see port 25 after opening it with the above access-list, shouldnt i? i enter in what i think is a correct access-list (like the 1st one in the 1st post) which should blow my firewall wide open, but i go and have it scanned... and it doesnt see anything at my ip (outside interface of the pix). im just rather confused.

is there a possibility of a faulty pix?

thanks for all the help so far....

 

[davarg]

I don't know anything about port scanning, but do you have a device on the inside listening on port 25 (with a static entry on the pix). I've had to do something similar with a webserver port 80, and I did the above (my last post). Ofcourse, I could never get to my webserver unless I had a static entry for the port. I'm still not sure whether you can scan the open port on the outside ip of the pix if the WebServer did not exist nor if it had a static entry.

I hope this helps

I

 

[soulofmischief]

i just figured that the nat on the pix would point it back to teh requesting box... dont know if it does or not...


all right tho... i got a port scan to see port 25 as closed. thats a step in the right direction. i used the static (pointed at my box) and the acl.

well if i goto any other machine on the network, it also sees that boxes port 25....

but the problem is still there. if i telnet to the email server port 25 from inside the network.... it takes a hugh amount of time before it finally connects. from the soho, it connects instantly.

so i remove both rules, wr mem, reload. while im waiting i clear cookies/ie cache on both the machines i ran the port scans on.

pix comes online, port scan shows 25 as closed. delete cookies/ie cache.

re-enter the static and acl, wr mem, reload.

the ports are, once again, not seen.

this thing will be the death of me.

thanks again tho davarg