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Point to Point T1 setup

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doug04

IS-IT--Management
Joined
Jan 16, 2004
Messages
50
Location
US
ok, I setup 2 1721 routers (with csu/dsu cards) on our point to point (PTP) T1 line with 2 multi-homed win2k servers on each end. Both ethernet0 and serial0 interfaces are line up and looking good on the routers. What I need to know.. what IP addresses should I assign to the interfaces? My situation is this:
I currently have a Linksys VPN link on a seperate T1 so I have remote control of the server and router on the other end. Each server has 2 NIC's one for the LAN and one to the router.
My LAN IP's are
192.168.1.x (LAN1)
192.168.57.x (LAN2) both with 255.255.255.0 subnet.

Should the routers be on a different subnet? if so what? I plan on closing the linksys VPN once I get the PTP going.

Any suggestions are much appreciated.
 
You need to allocate an unused private address to the WAN, or run it un-numbered. I prefer to allocate address, makes testing easier.

Allocate an unused IP address to each ethernet port

In this example I've taken a portion of 10.0.0.0 to use for the WAN link.
try this:

LAN1 router 192.168.1.1
WAN port 10.255.255.1 255.255.255.252
static route to access LAN2:
ip route 192.168.57.0 255.255.255.0 10.255.255.2

LAN2 router 192.168.57.1
WAN port 10.255.255.2 255.255.255.252
static route to access LAN2:
ip route 192.168.1.0 255.255.255.0 10.255.255.1

enable classless routing on both routers, this should be on by default if they are running a recent IOS.
 
so If I understand...

have no IP on the serial0 on either end..

the Fastethernet0's should be 10.255.255.1 255.255.255.252
and 10.255.255.2 255.255.255.252

then my LAN NIC's need to be what? 10.255.255.3 and .4? .4 says the subnet wont work.
 
BTW, here is the #2 1721's status..

FastEthernet0 is up, line protocol is up
Hardware is ********, address is **************
Internet address is 10.255.255.2/30
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:04:41, output 00:00:02, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
13214 packets input, 1357636 bytes
Received 13214 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
32462 packets output, 1947720 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Serial0 is up, line protocol is up
Hardware is PQUICC with Fractional T1 CSU/DSU
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input 00:00:06, output 00:00:01, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1158 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
37705 packets input, 2338651 bytes, 0 no buffer
Received 37705 broadcasts, 0 runts, 1 giants, 0 throttles
139 input errors, 5 CRC, 36 frame, 0 overrun, 0 ignored, 98 abort
37705 packets output, 2354543 bytes, 0 underruns
0 output errors, 0 collisions, 41 interface resets
0 output buffer failures, 0 output buffers swapped out
3 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
 
I should've mentioned, that the routers are connected to crossover cables into servers and not into a LAN, although they may be soon since our phone system might use the T1 as well so I'd need to get some switches on the end instead of the servers.
 
Not quite... What I meant by <Allocate an unused IP address to each ethernet port> was at LAN1 use an address from 192.168.1.x.

LAN2 use an address from 192.168.57.x

Apply the 10.255.255.1 and 2 addresses to the S0 ports at either end of the T1.

Then apply the static routes. The last Ip address in each route is the next hop, and this is the address at the remote end of the T1.

So if you end up with LAN1 router's S0 port IP as 10.255.255.1 then the static route to point to the remote end would be:

ip route 192.168.57.0 255.255.255.0 10.255.255.2


Hope that is a bit clearer, a diagram would help here to explain.
 
ok, thats clearer. Thanks.
 
ok, next problem. I cant seem to ping the other end of the networks. heres my config on the first router..

service timestamps debug uptime
service timestamps log uptime
no service password-encryption
no service tcp-small-servers
no service udp-small-servers
!
hostname ******
!
enable password ***********
!
no ip name-server
!
ip subnet-zero
no ip domain-lookup
ip routing
!
interface FastEthernet 0
no shutdown
ip address 192.168.57.152 255.255.255.0
keepalive 10
!
interface Serial 0
no shutdown
service-module t1 clock source line
service-module t1 data-coding normal
service-module t1 remote-loopback full
service-module t1 framing esf
service-module t1 linecode b8zs
service-module t1 lbo none
service-module t1 remote-alarm-enable
ip address 10.255.255.1 255.255.255.252
encapsulation hdlc
!
ip classless
!
! IP Static Routes
ip route 192.168.1.0 255.255.255.0 10.255.255.2 1 permanent
no ip http server
snmp-server community public RO
!
line console 0
exec-timeout 0 0
password ***********
login
!
line vty 0 4
password ***********
login
!
! The following commands are not recognized by Cisco ConfigMaker
! and are therefore appended here.
!
service config
service timestamps debug datetime msec
service timestamps log datetime msec
!
interface FastEthernet 0
speed auto
full-duplex
snmp-server enable traps tty
!
end

anything wrong here?
 
here is the show ip int from router #2..

FastEthernet0 is up, line protocol is up
Internet address is 192.168.1.252/24
Broadcast address is 255.255.255.255
Address determined by setup command
MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is disabled
Multicast reserved groups joined: 224.0.0.9
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Local Proxy ARP is disabled
Security level is default
Split horizon is enabled
ICMP redirects are always sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is enabled
IP fast switching on the same interface is disabled
IP Flow switching is disabled
IP CEF switching is disabled
IP Fast switching turbo vector
IP multicast fast switching is disabled
IP multicast distributed fast switching is disabled
IP route-cache flags are Fast
Router Discovery is disabled
IP output packet accounting is disabled
IP access violation accounting is disabled
TCP/IP header compression is disabled
RTP/IP header compression is disabled
Policy routing is disabled
Network address translation is disabled
WCCP Redirect outbound is disabled
WCCP Redirect inbound is disabled
WCCP Redirect exclude is disabled
BGP Policy Mapping is disabled
Serial0 is up, line protocol is up
Internet address is 10.255.255.2/30
Broadcast address is 255.255.255.255
Address determined by setup command
MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is disabled
Multicast reserved groups joined: 224.0.0.9
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Local Proxy ARP is disabled
Security level is default
Split horizon is enabled
ICMP redirects are always sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is enabled
IP fast switching on the same interface is enabled
IP Flow switching is disabled
IP CEF switching is disabled
IP Fast switching turbo vector
IP multicast fast switching is disabled
IP multicast distributed fast switching is disabled
IP route-cache flags are Fast
Router Discovery is disabled
IP output packet accounting is disabled
IP access violation accounting is disabled
TCP/IP header compression is disabled
RTP/IP header compression is disabled
Policy routing is disabled
Network address translation is disabled
WCCP Redirect outbound is disabled
WCCP Redirect inbound is disabled
WCCP Redirect exclude is disabled
BGP Policy Mapping is disabled
 
I enabled the internal clock on the s0 service-module's because I remebered our provider said the line didn't have one. Still no ping.
 
That looks OK, I would have expected that if you connect to R1 you should be able to ping 10.255.255.2 over the T1. If that works you should be able to ping 192.168.1.252. This would indicate the T1 is ok.

Let me know the outcome.
 
yes both those pings worked fine from within the router. But they do not work if I do it from my machine on the network (my desktop is 57.21). Right now R1 is into our 57.x network but R2 is just into a server at 1.250 My 57.21 gateway is our linksys proxy so its probably trying to go through the VPN I have setup? So maybe its working, but routing is trying other things???
 
Sounds like the routing is still not quite correct.

The router on 192.168.1.n, this needs a static route:

ip route 192.168.57.0 255.255.255.0 10.255.255.1

Also your PC, what is its default gateway?

If its your linksys, 57.21 then that unit needs a route adding, pointing to 192.168.1.0 via 192.168.57.152

The server will also need a default route pointing at its local router.

Once these routes are in place you should be able to ping the server.

Just one point, the linksys, does it have any filters applied to the LAN interface on the 57.0 network?
 
rather than have 2 routers on the same network I think it would be better to isolate the PTP T1 on a different network like 192.168.2.0 255.255.255.0. The only things using the PTP T1 are going to be our phone system and 2 servers, 1 on each end. So if I have each server multi-homed with a gateway of the cisco routers F0 int, then it should work ok? In this case, I'd keep our linksys VPN connection.
 
ok, I have both routers setup:
Server #1: 192.168.3.20/24
F0 on router #1: 192.168.3.1/24
S0 on router #1: 10.255.255.1/30
S0 on router #2: 10.255.255.2/30
F0 on router #2: 192.168.2.1/24
Server #2: 192.168.2.20/24

The DNS on each server is set to nothing. Server #1 has DNS running so its set to loopback.
Logged into either router, I can ping anywhere I want.
I can ping from server1 to F02 and server2 to F01.
I CANNOT ping from either server to server.

Do I need static routes in my remote access tables and if so, what? I have all 3 protocols (tcp/ipx/netbios) on both adapters. Any clues???
Thanks for the previous help. I see IOS in my sleep now. :p
 
Each server needs either the default gateway setting to point at the local F0 port, or a static route to the remote network, again via the local F0 port. I would use the first method.

Also each router needs a static route pointing to the remote LAN subnet. These routes use the remote WAN address as the next hop.

From the description of the ping tests it sounds like these static routes are missing from the routers.

Have a look at `show ip route' on each router, what does it show?
 
from router #2 - show ip route:
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

10.0.0.0/30 is subnetted, 1 subnets
C 10.255.255.0 is directly connected, Serial0
C 192.168.2.0/24 is directly connected, FastEthernet0
192.168.3.0/24 is variably subnetted, 2 subnets, 2 masks
S 192.168.3.0/30 [1/0] via 10.255.255.1
S 192.168.3.0/24 [1/0] via 192.168.3.1
 
router #1:
Gateway of last resort is not set

10.0.0.0/30 is subnetted, 1 subnets
C 10.255.255.0 is directly connected, Serial0
192.168.2.0/24 is variably subnetted, 2 subnets, 2 masks
S 192.168.2.0/30 [1/0] via 10.255.255.2
S 192.168.2.0/24 [1/0] via 10.255.255.1
C 192.168.3.0/24 is directly connected, FastEthernet0

how do I delete a static route in that router #2.Would it be &quot;no ip route 192.168.3.0/30&quot; ??
 
ok, I added

S* 0.0.0.0/0 [1/0] via 10.255.255.2

to each one now they say
Gateway of last resort is 10.255.255.2 to network 0.0.0.0

10.0.0.0/30 is subnetted, 1 subnets
C 10.255.255.0 is directly connected, Serial0
S 192.168.2.0/24 [1/0] via 10.255.255.2
C 192.168.3.0/24 is directly connected, FastEthernet0
S* 0.0.0.0/0 [1/0] via 10.255.255.2

AND WE HAVE SUCCESS!!! Heres the funny part.. I was thinking that I had to have routes in the Routing and Remote Access pointing to each step, but all I needed was to &quot;dumb down&quot; the route from 3.1 to 2.1 and vice versa.

Thanks for the clues people.
 
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