?
Solved

Networking different sites

Posted on 2005-03-11
14
Medium Priority
?
305 Views
Last Modified: 2011-09-20
We have got various sites that need to be interconnected. To simplify the explanation of the problem we will center on the networking of two sites.
Site A:
-Various PCs ranging from Win 98 to Win XP (IPs 192.168.124.xxx)
-One old server with Red hat Linux 7.x (IP 192.168.124.15)
-New Router (IP 192.168.124.100)
-Old ISDN router (IP 192.168.122.1)  (yes it is correct .122 !)

Site B:
-Various PCs ranging from Win 98 to Win XP (IPs 192.168.120.xxx)
-One old server with Red hat Linux 5.2 (IP 192.168.120.10)
-New Server running Unix (IP 192.168.120.253)
-Router (IP 192.168.120.254)
-Old ISDN router (IP 192.168.120.1)

Linux servers use to be connected using the old ISDN routers and worked perfectly.
We want to get rid off those ISDN lines and routers and have the connection using the new routers
New data is in the new Unix server and this can be accessed from all sites without problems.
The "old" Linux servers will still have to be accessed for some time.

Tests made from site A:
1-From any PC in A we can make ping to any PC in B
2-From the Linux server in A we can NOT make a ping to PCs in B
3-From the Linux server in A we can NOT make a ping to the Linux server in B
4-From the Linux server in A we can make a ping to the new router in A
5-From the Linux server in A we can make a ping to the new router in B
6-Pcs in A can work with new Unix server in B
7-Ping from any PC in A can see old Linux server in A (that is correct from A to A)
8-Ping from old Linux Server in A can see PCs in A (that is correct from A to A)

Tests made from site B:
1-Ping from old Linux server in B can NOT see PCs in A
2-Ping from old Linux server in B can NOT see new router in A  (.124.100)
3-Ping from old Linux server in B can NOT see old Linux server in A
4-Ping from any PC in B can NOT see old Linux server in A
5-Pcs from B can work with old Linux server in B
6-Ping from any PC in B can see any PC in A
7-Ping from any PC in B can see new router in A  (.124.100)


I need to achieve the following:
-PCs from A will have to work with old Linux server in B
-Pcs from A will have to work with new Unix server in B (this is working)
-Old Linux server from A will have to work with old Linux server in B

-PCs from B will have to work with old Linux server in A
-Pcs from B will have to work with new Unix server in B (this is working)
-Old Linux server from B will have to work with old Linux server in A.


Need to know how to achieve and set up this.

TIA
0
Comment
Question by:moose25
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 8
  • 3
  • 3
14 Comments
 
LVL 38

Expert Comment

by:wesly_chen
ID: 13519292
Hi,

   This can be done by VLAN (Virtual LAN) on router or switch level.
1. First, make sure SiteA and SiteB can connect each other by dedicated line or VPN.
2. Create VLANs on router or switch, which need to have VLAN feature, to separate the PC and Linux/Unix on SiteA and SiteB.
   Say vlan(A1) for PCs and vlan(A2) for Linux on SiteA. Then vlan(B1) for PCs and vlan(B2) for Unix on SiteB.
   Or add more VLANs for small group of PCs so you can restrict each vlan to other vlan.
Check your HW for details setting of VLAN access policy/rule.

Regards

Wesly
0
 

Author Comment

by:moose25
ID: 13520097
I think the problem resides on the configuration of the Linux Boxes.
Both sites are connected and working using "new" Unix server on site B
Both sites can "see" each other thru the Win boxes as you can see above.

Other ideas
0
 
LVL 38

Expert Comment

by:wesly_chen
ID: 13520203
Ok, check the iptables (RH5.2 may not have iptables) or ipchains on Linux boxes.
/etc/init.d/ipchains status
/etc/init.d/iptables status

Turn then off first.
/etc/init.d/ipchains stop
/etc/init.d/iptables stop

Also check /etc/hosts.allow and /etc/hosts..deny
to see the IP addresses match the change or not.

Wesly
0
What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

 

Author Comment

by:moose25
ID: 13521359
Ok I wil try that but since I am not at either site I would like to have as many  solutions as possible so that with one visit / remote connection to the sites could solve the problem.

The gateway's IP of the Linux box at site A has been changed to the correct one (192.168.124.100) and that allows to have a successfull ping to router in Site B (192.168.120.254). Why can't I ping from the Linux box in site A to the Linux Box in site B?
0
 
LVL 38

Expert Comment

by:wesly_chen
ID: 13521411
Hi,

   The default gateway setting at Linux box at Site A.
Make sure the default gateway is set to IP 192.168.124.100.
netstat -rn
route add default gw 192.168.124.100

Wesly
0
 

Author Comment

by:moose25
ID: 13521834
That has been checked. Otherwise I couldn't ping form Linux box at site A to router at site B. Yet, if I reach router at site B why can't I ping Linux box at B or even PCs at B FROM the Linux box at A?
0
 
LVL 9

Accepted Solution

by:
e-tsik earned 1500 total points
ID: 13523416
Hi  :-)

Just to make sure. Could you a check such as this?

On 192.168.124.15

1.
route del -net 0.0.0.0./0
route del -net 0.0.0.0./0
route del -net 0.0.0.0./0
(three times)
route add default gw 192.168.124.100
traceroute -n 192.168.120.253
ping IP 192.168.120.254
ping IP 192.168.120.253
telnet ping IP 192.168.120.253

2.
route add -host 192.168.120.254 gw 192.168.124.100
route add -host 192.168.120.253 gw 192.168.124.100
traceroute -n 192.168.120.253
ping IP 192.168.120.254
ping IP 192.168.120.253
telnet ping IP 192.168.120.253

We have to make sure that this is not a routing issue.
Hope it's useful...
0
 

Author Comment

by:moose25
ID: 13529512
I will try that but impossible to do it until wednesday or so.
Yes it could be a routing issue
Any more ideas I could try/check on wednesday.
Anything admitted.
Thanks
0
 

Author Comment

by:moose25
ID: 13538295

Answers to some of the points mentioned previously:

 
--/etc/init.d/ipchains status
Chain input (policy ACCEPT):
Chain forward (policy ACCEPT):
Chain output (policy ACCEPT):

-/etc/init.d/iptables status
Does not accept command

-/etc/init.d/ipchains stop
Flushing all chains:                                       [  OK  ]
Removing user defined chains:                              [  OK  ]
Resetting built-in chains to the default ACCEPT policy:    [  OK  ]

-/etc/init.d/iptables stop
Stops everything and disconnects


-netstat -rn

-route add default gw 192.168.124.100
Does not accept command
0
 
LVL 9

Expert Comment

by:e-tsik
ID: 13538596
Exactly on which host did it not accept 'route add default gw 192.168.124.100' ?
Could you post the output of
ifconfig
route -n

On that host?
0
 

Author Comment

by:moose25
ID: 13563671
in site B
---------
route add default gw 192.168.124.100

gives
SIOCADDRT: Network is unreachable


route add default gw 192.168.120.254
gives
SIOCADDRT: File exists


ifconfig from site B (192.168.120.19) with gateway 192.168.120.254
eth0      Link encap:Ethernet  HWaddr 00:10:5C:AB:26:19
          inet addr:192.168.120.10  Bcast:192.168.120.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1269327 errors:0 dropped:0 overruns:0 frame:31
          TX packets:426505 errors:0 dropped:0 overruns:0 carrier:0
          collisions:1869 txqueuelen:100
          Interrupt:17 Base address:0xe800

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:3924  Metric:1
          RX packets:9538 errors:0 dropped:0 overruns:0 frame:0
          TX packets:9538 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0

and route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.120.10  0.0.0.0         255.255.255.255 UH    0      0        0 eth0
192.168.120.0   192.168.120.10  255.255.255.0   UG    0      0        0 eth0
192.168.120.0   0.0.0.0         255.255.255.0   U     0      0        0 eth0
127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        0 lo
0.0.0.0         192.168.120.254 0.0.0.0         UG    0      0        0 eth0
0.0.0.0         192.168.120.1   0.0.0.0         UG    0      0        0 eth0

A telnet from server in site B (.120.10) to server in site a (.124.15) gives "no route to host)

in site A
---------
route add default gw 192.168.124.100
gives
SIOCADDRT: File exists

ifconfig
gives

eth0      Link encap:Ethernet  HWaddr 00:E0:18:1E:4A:53
          inet addr:192.168.124.15  Bcast:192.168.124.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:27972 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5699 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          Interrupt:11 Base address:0x1800

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:4748 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4748 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0

route -n
gives
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.120.10  192.168.124.100 255.255.255.255 UGH   0      0        0 eth0
192.168.120.253 192.168.124.100 255.255.255.255 UGH   0      0        0 eth0
192.168.120.254 192.168.124.100 255.255.255.255 UGH   0      0        0 eth0
192.168.124.0   0.0.0.0         255.255.255.0   U     0      0        0 eth0
127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        0 lo
0.0.0.0         192.168.124.100 0.0.0.0         UG    0      0        0 eth0

0
 

Author Comment

by:moose25
ID: 13563964
Results again from:
ust to make sure. Could you a check such as this?

On 192.168.124.15

1.
route del -net 0.0.0.0./0
route del -net 0.0.0.0./0
route del -net 0.0.0.0./0
(three times)
route add default gw 192.168.124.100
tetc, etc

-------------------------ooOoo----------------

route del -net 0.0.0.0./0
gives
0.0.0.0.: name of `host' not found

so substituted by ( no last  "." )
 done 3 times as asked
SIOCDELRT:does no exist such process

route add default gw 192.168.124.100  (ok. gives no answer, error, comments etc..)

traceroute -n 192.168.120.253
gives
traceroute to 192.168.120.253 (192.168.120.253), 30 hops max, 38 byte packets
 1  192.168.124.100  2.304 ms  0.817 ms  0.814 ms
 2  * * *
 3  * * *
 4  * * *
 5  * * *
 6  * * *
 7  * * *
 8  * * *
 9  172.24.0.2  137.455 ms  137.483 ms  143.781 ms
10  192.168.120.253  131.953 ms  131.955 ms  132.142 ms


ping IP 192.168.120.254
gives
unknown host IP

while
ping 192.168.120.254 responds OK

ping 192.168.120.253 responds OK

telnet ping 192.168.120.253
gives
ping: Host name lookup failure


2 set of tests

route add -host 192.168.120.254 gw 192.168.124.100
gives
SIOCADDRT: File exists

route add -host 192.168.120.253 gw 192.168.124.100
gives
SIOCADDRT: File exists

traceroute -n 192.168.120.253
gives
traceroute to 192.168.120.253 (192.168.120.253), 30 hops max, 38 byte packets
 1  192.168.124.100  0.954 ms  0.823 ms  0.826 ms
 2  * * *
 3  * * *
 4  * * *
 5  * * *
 6  * * *
 7  * * *
 8  * * *
 9  172.24.0.2  133.671 ms  257.896 ms  174.098 ms
10  192.168.120.253  137.937 ms  131.945 ms  335.799 ms

ping IP 192.168.120.254
gives
unknown host IP

while
ping 192.168.120.254 responds OK

telnet ping 192.168.120.253
gives
ping: Host name lookup failure

Any other ideas

0
 
LVL 9

Expert Comment

by:e-tsik
ID: 13564959
First
route del -net 0.0.0.0./0
Should have been
route del -net 0.0.0.0/0

And
ping IP 192.168.120.254
telnet ping 192.168.120.253

Should have been
ping 192.168.120.254
telnet 192.168.120.253

You seem to have a ping between the servers. The telnet test should see the other unix. If successful, then the clients from the other side should be able to access the Linux server.
0
 

Author Comment

by:moose25
ID: 13572581
Problem solved with the instructions:
route del -net 0.0.0.0/0
route del -net 0.0.0.0/0
route del -net 0.0.0.0/0
route add default gw 192.168.124.100
route add -host 192.168.120.254 gw 192.168.124.100
route add -host 192.168.120.253 gw 192.168.124.100

Thanks
0

Featured Post

On Demand Webinar: Networking for the Cloud Era

Did you know SD-WANs can improve network connectivity? Check out this webinar to learn how an SD-WAN simplified, one-click tool can help you migrate and manage data in the cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I have seen several blogs and forum entries elsewhere state that because NTFS volumes do not support linux ownership or permissions, they cannot be used for anonymous ftp upload through the vsftpd program.   IT can be done and here's how to get i…
Note: for this to work properly you need to use a Cross-Over network cable. 1. Connect both servers S1 and S2 on the second network slots respectively. Note that you can use the 1st slots but usually these would be occupied by the Service Provide…
If you're a developer or IT admin, you’re probably tasked with managing multiple websites, servers, applications, and levels of security on a daily basis. While this can be extremely time consuming, it can also be frustrating when systems aren't wor…
Visualize your data even better in Access queries. Given a date and a value, this lesson shows how to compare that value with the previous value, calculate the difference, and display a circle if the value is the same, an up triangle if it increased…
Suggested Courses

770 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question