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dhcp / 1700 1

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guydv

Technical User
Joined
Aug 2, 2007
Messages
9
Location
IL
hello -
need help with dhcp problem with my router ...
it works 100% with the adsl (wic) it get ping but dhcp / wll - work and dont work ... my config is very easy

!
!
!
ip dhcp pool Home
network 10.25.25.0 255.255.255.0
default-router 10.25.25.254
dns-server 192.115.106.10
!
!
ip name-server 192.115.106.10
ip cef
no scripting tcl init
no scripting tcl encdir
!
!
!
!
interface ATM0
no ip address
load-interval 30
no atm ilmi-keepalive
pvc 8/48
dialer pool-member 1
protocol ppp dialer
!
dsl operating-mode auto
!
interface Ethernet0
ip address 10.0.0.254 255.255.255.0
ip nat inside
half-duplex
!
interface FastEthernet0
ip address 10.25.25.254 255.255.255.0
ip nat inside
speed auto
hold-queue 100 out
!
interface Dialer0
ip address negotiated
ip nat outside
encapsulation ppp
load-interval 30
dialer pool 1
dialer-group 1
no cdp enable
ppp pap sent-username mrfresh@014 password 0 q1w2e3
!
ip nat inside source list 111 interface Dialer0 overload
ip classless
ip default-network 0.0.0.0
!
ip nat inside source list 111 interface Dialer0 overload
ip classless
ip default-network 0.0.0.0
ip route 0.0.0.0 0.0.0.0 Dialer0
no ip http server
!
!
access-list 111 permit ip any any
dialer-list 1 protocol ip permit
!
control-plane
!
!
line con 0
line aux 0
line vty 0 4
login local
!
scheduler max-task-time 5000
!
end
 
What does not work? Do nodes not get an IP address from the router? Exactly what model is the router? I can't remember, but is the fast ethernet interface built in? What does show ip dhcp binding show? What about show ip dhcp pool?

Burt
 
Also, I think DHCP service depends on IOS features/version.

EB
 
If the router took the commands, which in this case it clearly did, then the feature is supported.

Burt
 
here is the cisco link for dhcp config


one thing since your not using an agent or external database it says you should run the command
Router(config)# no ip dhcp conflict logging

by default its supposed to be enabled..
but you may want to run
Router(config)# service dhcp
just to be sure...
 
ok...Go easy on me :-)
here it's gos -
i get 2 pc's pc1 when i try to reper the nic it would not go - even thou it get the ip when it boot up but will not reper - pc2 will reper when ever i do... but!!!
i some time losing surf when i log to the router i can ping the dns 100% but i cant ping a after a wating all goes good...
p.s -
using 1700 with adsl nic and the fast ethernet
p.s what is "ip dhcp binding show"
any want to "rdp" me :-)
 
I have no idea what you are asking or what your problem is...sorry.

Burt
 
just set static ips on your pcs then if you only have 2?
 
ok.. i will try a gain :-)
i use a 1700 cisco (wic-adsl) router that's linke up to the a swith throw the fastethernet (on the router)
now - this what's happing - let's say i am surfing, out of the blue i cant surf any more - so i log on into the router and using the ping command (inside the router) i see i get 100% ping to any site (inside the router) but when i try to surf with my pc - i cant.
some how the problem fis its self and i can keep on surfing....
hope that a better explain :-)
thanks
 
If you are able to get out to the internet initially, but then suddenly cannot, I would suspect either a cable or something on the ISP end, or perhaps your MTU (being DSL, this is the likely culprit). Do this...
router>en
router#conf t
router(config)#int di0
router(config-if)#ip tcp adjust-mss 1452
router(config-if)#end
router#wr
Then download drtcp from here...
and install on your computer and follow the instructions so that the MTU on the packets going out are 1492 octets.
The second drtcp thing is optional, though it helps. You really do need to adjust mtu in the router the way I suggested though.

Burt
 
are there errors on the switch? maybe your ports to the pcs are taking errors
 
WOw thank's Guy's
Burt i did not get it - should i change the router setting or not ??
i downloaded the dr tcp and changet the mtu as you asked...
p.s - what is mtu ???

about the switch wll it an Hp procurve and even when the surfing stops i still can ping my router 100%
 
Have you tried using a known good laptop directly connected to the ethernet with a static ip?

You state that all seems to work okay then it stops... You can ping internet ip's from the router but not the PC's.. Use the extended ping command with a source of and internal ip address...

Verify NAT translations...

“Reserve your right to think, for even to think wrongly is better than not to think at all”

Tek-TIP Member 19,650
[americanflag]
 
HI JETTER
yes i treid but what is the ex-ping coomand and how do i use it

and nat ??? how do i cheak it ???
p.s at this time i put my pix 501 to work ..let see this one...
i will keep u up to date...
 
NAT translations seem to be working if he can get out to the internet for a while. Yes, guydv---change the mtu setting in the router. MTU is Maximum transmission unit, and there are 2 values that can be changed---layer 3 (IP) and layer 4 (TCP)---usually in Cisco routers, depending on the version of IOS, either one is changed. In later versions (can't remember the version where it started), ip tcp adjust-mss can be used. The TCP information carried in an IP header should be adjusted to 1452 for DSL connections, and the total MTU will then be 1492, as the IP header itself that is sent in IP is 40 bytes. Sometimes, especially with DSL, 1500 (the standard MTU size for IP) is too much, so a packet coming back in will hang. I have noticed this myself with certain websites (like Cisco.com, for example!). It is hard to say without actually being there where you are...jeter is onto something with IP NAT translations.
router#clear ip nat trans
will clear the translations out of the cache, but this is usually affected on large networks with a lot of translations taking place.
Here is a good document on MTU...

Burt
 
Hi
How do u know all that - i will kill to know the lyer stuff and how it connect with the cisco routers
so how do i change it ?

Router_F(config-if)# mtu 1500
Router_F(config-if)# shutdown
Router_F(config-if)# no shutdown
Router_F(config-if)# ^Z
(p.s would like to RDP me...?
ahh- the pix work's fine
 
router>en
router#conf t
router(config)#int e0
router(config-if)#ip mtu 1492
router(config-if)#exit
router(config)#int fa0
router(config-if)#ip mtu 1492
router(config-if)#exit
router(config)#int di0
router(config-if)#ip tcp adj-mss 1452
router(config-if)#end
router#wr

If the e0 and fa0 interfaces do not accept the
router(config-if)#ip mtu 1492
then you can still do this on each interface instead...
router(config-if)#ip tcp adj-mss 1452

Burt
 
ok.. will do
p.s - the pix still works 100%
say..is the pix 501 is faster then using 1700 + wic ?
 
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