Re: Re: Re: Re: IP filtering

BTW -

I turned on IP filter journalling and there are 3 identical journal entries
generated when I try to get to 172.17.26.48:80 . . . they look like this:

ETHLINE   A I    3   610.10.18.111    1885172.17.26.48      8010.10.18.111
188510.10.18.54       80

This appears (to me) to indicate that the AS/400 at 172.17.26.48 is
receiving the packet from my PC at 10.10.18.111 and attempting to forward it
to 10.10.18.54 but it isn't getting there for some reason.

Unfortunately, the InfoCenter link for journal code M, type TN points to the
"TCP/IP Configuration and Reference" manual - which doesn't contain a
*THING* about journal entries!  Wonderful!

Thanks again,

Steve

"Steve McKay" <steve.mckay@xxxxxxxxxxxxxx> wrote in
message news:brvopc$n6q$1@xxxxxxxxxxxxxxxx

Yep - clear as mud - so can you help me here?

1. From my PC at 10.10.18.111, I point my browser at 172.17.26.48 port 80.

2. My request is examined by TCP/IP and it is determined to be destined

for

another subnet so it is sent to the router at 10.10.18.1 (all routers on

our

network = 1 in the 4th octet).

3. My request leaves the 10.10.18.1 router and goes along on the network
until it hits the 172.17.26.1 router.

4. The 172.17.26.1 router examines my request and "pushes" it to the test
AS/400 at 172.17.26.48. When the request hits the test /400, the IP

packet

rules kick in:

ADDRESS frontend   IP = 172.17.26.48   TYPE = BORDER
ADDRESS backend   IP = 10.10.18.54   TYPE = TRUSTED
HIDE backend:80   BEHIND frontend:80   TIMEOUT = 16   MAXCON = 512   JRN =
OFF

Since 172.17.26.48 port 80 is "hiding" 10.10.18.54 port 80, I would expect
the test /400 to re-direct my packet back to 10.10.18.54. (This is the

part

that I don't understand . . . why isn't the packet "forwarded" to
10.10.18.54 port 80 at this point?)

I'm sure you've spent more time than you wanted on this but I sure
appreciate your help!

Thanks,

Steve


"Kirk Goins" <kgoins@xxxxxxxxxxx> wrote in
message news:3FE34A99.6040509@xxxxxxxxxxxxxx

In short yes...

IP works like this...
#1The destination IP address is compared with source IP and its network

mask

   in your case 172.17.26.48 and 255.255.255.0 and 10.10.10.25.
#2 Since  10.10.10.x isn't the same as 172.17.26.x  it sends the packet
to it's
    gateway at 172.17.26.y
#3 That gateway device sends it along its way to the 10.10.10.x network
#4  At the router that connects to the 10.10.10.x  it looks up where
10.10.10.54 is
      and send it directly to it (bypassing the 400)

Now your 1st  config with both on 10.10.10.x
#1 It compares the source address 10.10.10.x with the source 10.10.10.x
#2 It matched and sends the packet directly to the 10.10.10.84 not going
thru the 400 again.

The reason it worked when everything was on the 400, was the 400 had
control of the both addresses
where it does it in the 2 other cases above.

Clear as mud?



Steve McKay wrote:

Kirk -

Thanks for your help.

Yes, the netmask for both is 255.255.255.0. Since I am in a

departmental

IT

group, I have no control over the corporate network topology - IOW, I

have

no ability or authority to change subnets or reassign default gateways.

We have another test system which is on a separate segment (IP addr
172.17.26.48). I tried using it as the front-end, pointed to

10.10.18.54

but got the same results.  Is this due to your
statement -

If you decide to change the network address to 10.10.19.x then ALL

devices

in the 10.10.18.x network must have their default gateways pointing to

the

400 at 10.10.18.25.

????

Thanks,

Steve



<kirkg@xxxxxxxxxxxxx> wrote in message

news:OF5BCA95B8.F4798FC5-ON88256DFF.0051B683-88256DFF.00546D7B-Nev6iVHbUkIQ
VHkZcc7xNw@xxxxxxxxxxxxxxxx

I think your problem is in the basics of how IP works. Without seeing

the

netmask, I'm betting both of these IPs are most likely subnet,
255.255.255.0. If that is true, then no routing or filtering can take
place the way you want.

Think of it has everyone on 10.10.18.x being on a party line, everyone
here's everyone else. You tell George(10.10.18.25) to not let
John(10.10.18.54) hear or say something. For your filtering to work a

few

things must happen. These must be thought out before you start

actually

doing any of this since I don't anything about your network.

Logically you must seperate 10.10.18.25 and .54 on to seperate

networks.

If the number of devices are small you could change the netmask to say
255.255.255.224. This would create 8 32 address networks
1-31, 32-63, 64-95 etc. If you need more than that then you will need

to

change the subnet itself to say 10.10.19.x for the .54 address.

If you decide to change the network address to 10.10.19.x then ALL

devices

in the 10.10.18.x network must have their default gateways pointing to

the

400 at 10.10.18.25.

There is more to this than above but's it's the basics. The main thing

is

the packets can't have a way around whatever is filtering. To get from

.25

to .54 and get filtered, they must be on different networks.

_____________________
Kirk Goins CCNA
Systems Engineer, Manage Inc.
IBM Certified iSeries Solutions Expert
IBM Certified iSeries e-Business Infrastructure
IBM Certified Designing IBM e-business Solutions
Office 503-353-1721 x106 Cell 503-577-9519
kirkg@xxxxxxxxxxxxx      www.manageinc.com

"Steve McKay" <steve.mckay@xxxxxxxxxxxxxx>
Sent by: web400-bounces@xxxxxxxxxxxx
12/17/2003 06:19 AM
Please respond to
Web Enabling the AS400 / iSeries

<web400@xxxxxxxxxxxx>

To
web400@xxxxxxxxxxxx
cc

Subject
[WEB400] Re: IP filtering

Further information -

If 10.10.18.25 and 10.10.18.54 are both defined interfaces on a single
iSeries, the filter rules work fine. Unfortunately, this is not what

I

need
to do - I need to use one system as a "traffic cop" to redirect

requests

to
a second system.

If 10.10.18.25 and 10.10.18.54 are on separate systems, the same

filter

rules as above do not work. I can only conclude that, when the IP

filter

rules change the IP address in the packet, the packet does not get put
back
out on the network.

Can anyone confirm or deny this?

Thanks,

Steve
"Steve McKay" <steve.mckay@xxxxxxxxxxxxxx>

wrote

in

message news:brdbpp$mr$1@xxxxxxxxxxxxxxxx

Greetings list!

I am attempting to forward HTTP requests from one iSeries Apache

webserver

to another on a private network (not VPN, just a non-Internet

Ethernet

network). I have created the following IP packet rules:

ADDRESS frontend IP = 10.10.18.25 TYPE = BORDER
ADDRESS backend IP = 10.10.18.54 TYPE = TRUSTED
HIDE backend:80 BEHIND frontend:80 TIMEOUT = 16 MAXCON = 512

JRN

=

OFF

When I activate the rules and point the browser to 10.10.18.25, I get

a

"Cannot find server or DNS error" message but if I go directly to
10.10.18.54, I get the expected website.

Any ideas?



_______________________________________________
This is the Web Enabling the AS400 / iSeries (WEB400) mailing list
To post a message email:

WEB400@xxxxxxxxxxxx

To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/web400
or email: WEB400-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/web400.

_______________________________________________
This is the Web Enabling the AS400 / iSeries (WEB400) mailing list
To post a message email:

WEB400@xxxxxxxxxxxx

To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/web400
or email: WEB400-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/web400.

_______________________________________________
This is the Web Enabling the AS400 / iSeries (WEB400) mailing list
To post a message email:

WEB400@xxxxxxxxxxxx

To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/web400
or email: WEB400-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/web400.

_______________________________________________
This is the Web Enabling the AS400 / iSeries (WEB400) mailing list
To post a message email: WEB400@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/web400
or email: WEB400-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/web400.

--
Kirk Goins CCNA
Systems Engineer, Manage Inc.
IBM Certified iSeries Solutions Expert
IBM Certified iSeries e-Business Infrastructure
IBM Certified Designing IBM e-business Solutions
Office 503-353-1721 x106 Cell 503-577-9519
kirkg@xxxxxxxxxxxxx      www.manageinc.com

_______________________________________________
This is the Web Enabling the AS400 / iSeries (WEB400) mailing list
To post a message email: WEB400@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/web400
or email: WEB400-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/web400.

_______________________________________________
This is the Web Enabling the AS400 / iSeries (WEB400) mailing list
To post a message email: WEB400@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/web400
or email: WEB400-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/web400.

_______________________________________________
This is the Web Enabling the AS400 / iSeries (WEB400) mailing list
To post a message email: WEB400@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/web400
or email: WEB400-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/web400.