Ticket 13 – DHCP Helper-address

New Packet Tracer Lab 13 on this site:

R4:

ip dhcp excluded-address 10.2.1.1 10.2.1.253

This was excluding the whole 10.2.1.0/24 network, PC1 won’t get an ip address.

conf t
no ip dhcp excluded-address 10.2.1.1 10.2.1.253
end
wr

*** I had to reload R4 too, if not, DHCP never would provide an ip to PC1, everything ok after reloading it.

The lab has other issues, as 10.1.1.8/30 network not declared in “router eigrp 10”

did not pass. I was confident that I answered all questions correctly since I am good at troubleshooting. Only sim that I could not find a correct answer for was: ipconfig on Client 1 showed 169.xx address. Obvioulsy not getting a DHCP address. When I looked at ASW1 (show run), the links to Client 1 and Client 2 were shutdown. Obviously if the link between host and Client are shutdown, the client will never get an IP address from the DHCP server. But I could not locate a Solution to the 3rd part of the question that also had “no shutdown” for Fa1/0/1. I do not like Cisco’s approach to testing since there is no recourse for an audit. Besides in the real-world one has a diagram (hard copy or on a separate monitor) plus tools such as Notepad++ to compare/highlight areas in configs.

“how to dhcp” is slightly wrong!

“ip dhcp excluded-address 10.2.1.1 10.2.1.2” IS a range (In this case only for 2 addresses):
R4(config)#ip dhcp excluded-address ?
A.B.C.D Low IP address
R4(config)#ip dhcp excluded-address 10.2.1.1 ?
A.B.C.D High IP address

The rest is correct. Thank you.

In Packet Tracer Sim, the range at R4 is “ip dhcp excluded-address 10.2.1.1 10.2.1.253”. In Fact all addresses are excluded since “ip dhcp excluded-address 10.2.1.254” is also configured on R4.
In Packet Tracer Sim the ip-helper address at vl10 on DSW1 is correct. I guess in real Exam you should check both just to make sure.

In GNS3 topology, sometimes you cannot get the IP address from DHCP server (R4) even after the rectification of IP-Helper address on DSW-1. The solution is to restart the VLAN 10 interfce on DSW-1 and try to get an IP from Client-1 after that.

Taking exam in 2 days and trying to figure out the correct answer, I know about no exclude command but do we put in an ip exclude command..or is it on DSW1 rather than R4..any help will do please

I passed the TSHOOT exam today. Got 1000. Nov 13th MCP/ HSRP and BGP Simlets /12 Labs from this website. All is here.

Becarefull with the IP helper lab. Even though the port security is on fa1/0/1 and fa1/0/2, the interfaces on “show ip int brief” are up/up, the issue was ip helper on DSW1.

I figured that out because of the status of the two access interfaces on ASW1.

Good luck guys
Thanks Networktut.

Passed 9XX/1000

MY GAME PLAN

-STUDY NULLZERO AND PING BY SAM
-MEMORIZE NOV AND SEPT 2013 (Actually only 1Q appeared from sept)
– Study HSRP and BGP (Both appeared on the exam)

DONT LISTEN TO OTHER BULLSHIT that some had changed on the exam.

P.S.

There is 1 ticket that
1. APIPA
2. DHCP helper address is incorrect on DSW1
3. Has Port Security on ASW1.

I just answered DHCP helper can someone confirm if this is the correct answer or not?

Thanks,
Jen

GOODLUCK GUYS!!!!

FYI you can still get an address because the client will use DSW2 to reach R4. Still, the correct answer for the *exam* will be changing the helper address on DSW1. If you don’t know what it us, just log into R4 and have a look to doublecheck

@Jenny_chey, it’s not bullshit that some changes are there. It appears as if Cisco has put in misleading clues, such as you mentioned. One ticket with APIPA and portsec, but port is not err-disable.

The tickets are valid, but extra caution is needed to verify the correct ticket. Once you know the problem, the answer is still the same as here. But the difficulty is finding the correct problem ticket.

-Anon

Here is my approach:

1) First verify the problem exist => unsuccessful ping from Client 1 to web server.
2)Ping R4(10.1.4.5 or 6) – unsuccesful. Go to R4 and try to ping webserver and it is successful. Now I know the problem is before R4 so I go back adn start checking my interfaces for any L1 issues. I see all the interfaces are up/up so no L1 issues. Need to verify L2 and L3 connectivity from client 1 to gateway.
3)Do a ipconfig on R1 and there is no gateway! Client 1 has APIPA meaning it cannot contact a DHCP server so it is auto configuring itself. Do a show run on the switches to check fr any DHCP leads

4)On DSW1 and DSW2 we see there is an IP address helper command for vlan 10 and looking at the topology client 1 is on vlan 10

5)DSW1 has an ip adress helper of 10.2.21.129 and DSW2 has an ip address helper of 10.2.1.129

6)We need to find the interface having this ip on the connecting router R4
On R4, issue sh ip int brief and Loopback 1 has an ip address of 10.2.1.129 so DSW1 has a wrong IP address

Therefore the problem is on DSW and it is DHCP related. The solution is to delete the wrong ip helper address 10.2.2.129 and add the right ip helper address of 10.2.1.129

@007
I think the right ip helper address should be 10.1.21.129?

Hi Henry
yes. my mistake. 3rd octet must be 21 always.
correct IP helper is 10.1.21.129 got full marks for everything

@☻buttmuch clients will not be able to get ip addresses as the active interface in the hsrp group is on dsw1