My catalyst cisco switch 3650 48 4x1g could not get ip from our linux based DHCP server

[evgenie.czernie1]

We have our DHCP server on the network, that dhcp server is working on linux and configuring all other switches and  PC desktop as usual,

we have 2960 plus switches mostly, but recently we purchased 3650 switch and we trying to configure it. Usually when the PC or Switch is booting on the network is geting IP and Hostname automaticaly from our DHCP server.

this one 3650 is not geting ip neigher hostname. and i don't know where is the problem.

can you help? 

usualy when we have this kind of a problem we delete *.text from the memory, i am attaching you the photo. i don't see any "text" files  in there. so i cannot understand the problem.

please help.

[Mark Malone]

Hey ok let start from scratch here

The 3650 and 2960s are they on the same vlan as the DHCP server ? If not you will need an ip helper address on the vlan interface

When the server/pc is connected to the 3650 are you getting a mac address on the port check with -----sh mac address-table interface x/x/x

Then when mac is confirmed wat is your layer 3 devic4e , you need to check that mac against the arp table ------- show ip arp x.x.x

There is no diff between how 2960 and 3650 opertate in terms of dhcp/mac/arp there image is just different ios-xe and ios

You should not be deleting files in flash unless you know exactly what they are , looking at your screenshot the 3650 has everything it needs so that's not your issue

Please post the above and we can go from there to resolve this

[evgenie.czernie1]

yes.

sh mac address-table GigabitEthernet1/0/1

empty table

sh ip arp GigabitEthernet1/0/1

nothing is happening just the same cli(switch#;switch#)

[Mark Malone]

Ok so why are you not getting mac address , that's not the switch , when a device connects to a switch by cable its layer 1 , the next step is the connected device sends its mac address by broadcast from its nic to the port , the switchport receives the mac address and then puts it in its cam table , after that the mac is then resolved to ip address by the layer 3 device through dhcp/arp

Is the port coming up /up when you connect the device ? what type of device is it ?

Try connect a standard laptop to the same  port and run the command again ?

[evgenie.czernie1]

NO. I will explain you again:

SW3650 >>(ethernet cable)>>SW2960>>(ethernet cable)>>DHCP SERVER

[Mark Malone]

Ok I think I get what your trying to do

but you cant pull a switch name from the a dhcp server , not unless your transferring the configuration file across and then uploading it from flash to the running-config

dhcp can send an ip / name to a pc or server but it cant configure a switch ? Even if your server sends a full conf file you would still need to transfer from flash to start-up using copy commands like

copy flash:Newconfigfile.text startup-config

Your using a 3650 just copy the conf file onto the 3650 by usb and transfer it start-up or use ftp or tftp

How exactly are you sending the file from your dhcp server to flash ?

[evgenie.czernie1]

first,

SW3650 needs to get an IP address and its Hostname because i made a DNS record in my DNS server(also PTR reccord), in addition i reffered MAC address of my SW3650 to his Hostname, also on my linux server where my DNS located also.

Before i was connecting other new SW2960P instead of SW3650 and it worked fine. The problem started when i was trying to configure SW3650.

and yes, after my SW3650 will get IP/HOSTNAME i will push him conf file using cli:

./load_cisco_conf    Hostname

rsh   Hostname   write memory

it should be [OK]

after these command will succed i will type "DIR" on my Hostname# and i should see the config.text file

tiendo?  :)

[Mark Malone]

Yes I get you just never heard of it been done like that before , usually just console in configure it etc ,  you could just manually do it

what way have you set the switch port up that connects to the 2960 , is it set for dhcp like ip address dhcp ?

  it wont automatically pull anything like the 2960 as theres another device in front of it , so it would need a default-gateway and the port set for dhcp at the very least

[Mark Malone]

2960 would work fine as its directly connected to the dhcp server

[evgenie.czernie1]

you don't understand:

before:

sw2960>>>sw2960>>>dhcp

now:

sw3650>>>sw2960>>>dhcp             sw3650 not geting ip   sw2960 does get ip

[Mark Malone]

I do understand I just dont know how you managed to get that working like that , without a default-gateway how would you expect the dhcp server to know where to send the information back too , without a source or return path ? 

[evgenie.czernie1]

because all the three(3) devices are on the same LAN, it uses ARP and MAC address of the SW3650 to get the IP from DHCP

[evgenie.czernie1]

what about this one what should i choose?

(see attached file)

[Mark Malone]

Thats if you want to go through setup manually and apply everything , it will run through basic start-up questions to get the switch online , every switch out of the box has auto install , you can chose to run through each question or just configure it yourself

[evgenie.czernie1]

so:

no   

no

?