DHCP RELAY on HTTP-Interface SWITCH X550X F24

[JensMoje25142]

Sorry Guys,

I want to set on easy away a dhcp relay , so that all lan cable get a ip from router ( 192.168.2.1 --> Fritzbox )

I SET on  IP Configuration

IPv4 Interface   OOB  static  192.168.2.254 mask 255.255.255.0 valid

on DHCp Relay

I put   IP 192.168.2.1  for DHCP  Server ( Router )

enable DHCP Relay

SET on DNS SERVER this switch   IP 192.168.2.254

So I hope, that I get all define, but my Laptop which is connected via cable on Switch get no IP address via DHCP.

Should I do another setup in IPv4 Interface ? Or what is the reason, that DHCP RELAY not work?  I connected router with OOB Port. I could access to X550X so, LAN Settings work, but DHCP is not working.

I thought that is so easy and I read some articel but, i could not found a solution.  I think, that is a very simple to solve, if someone has more experience than me

cu

Jens

[balaji.bandi]

192.168.2.1 --> Fritzbox - acting as router. your 550 switch acting as Layer 2 only then just configure as trunk port and connect to your router - so you DHCP IP address from your Router.

I am assuming your setup will be as below :

ISP --Fritzbox--SG550--PC

is this SG550X  switch ? if yes below configuration :

https://www.cisco.com/c/en/us/support/docs/smb/switches/cisco-small-business-300-series-managed-switches/smb5567-configure-dynamic-host-configuration-protocol-dhcp-relay-set.html

[JensMoje25142]

Hi BB,

sorry I am a beginner and the word layer 2 is such a unkown for me   Yes, i want only  ISP - FRITZBOX- SX550X 24F - PC,

What do you mean trunk port? I could not found such in the web inferface of cisco by this device. 

It is a SX550X-24F device and so much documents do i not found on cisco page.  I check your link, but i could not find some tipps for me. Should i work with CLI commands? The web interface is much better to work.

[balaji.bandi]

Lets make simple configuration - You can do basic setup following guide ( change the IP from 192.168.1.254 to 192.168.2.254 and gateway as 192.168.2.1) - leave the test as default VLAN (attached quick Guide to setup one) cehck from switch you able to ping 192.168.2.1

then configured DHCP relay as mentioned : this document

config t

!

ip dhcp relay enable

ip dhcp relay address 192.168.2.1

!

exit

copy run start ( save the config)

connect PC to one of the port set as DHCP - check are you able to get DHCP IP address from your Router range 192.168.2.X

[JensMoje25142]

Hello BB,

sorry for my delay.

I do you advice :  but it does not work

following data:

show ip dhcp relay
DHCP relay is Enabled
Option 82 is Enabled
Maximum number of supported VLANs without IP Address is 256
Number of DHCP Relays enabled on VLANs without IP Address is 1
DHCP relay is not configured on any port.
DHCP relay is enabled on Vlans: 1
Active: 1
Inactive:
Servers: 192.168.2.1

NETNWSW#show ip interface

IP Address I/F I/F Status Type Directed Prec Redirect Status
admin/oper Broadcast
------------------ --------- ---------- ------- --------- ---- -------- ------
192.168.2.254/24 oob UP/UP Static disable No enable Valid

I could ping and trace my fritzbox.

What could i do?

[Georg Pauwen]

Hello,

the SG550X is a layer2/3 switch by default. You need to go into 'System Settings' and check the radio button next to 'System Mode' 'L2'. 

With this setting, you basically don't need to configure anything on the switch for DHCP to work.

[JensMoje25142]

Hello Georg,

yes, all is layer mode 2.  I enable also dhcp relay and nothing work, if i put a cable on e.g. XG1   no ip will give over my fritzbox .

[Georg Pauwen]

Hello,

hard to tell what you are missing. Is the switch in layer 2 or layer 3 mode ? In the latter case, try and configure the relay from the command line:

SG550X#config
SG550X(config)#interface vlan 1
SG550X(config-if)#ip dhcp relay enable
SG550X(config-if)#ip dhcp relay address 192.168.2.1

[JensMoje25142]

I use putty, to give our commands

show ip dhcp relay
DHCP relay is Enabled
Option 82 is Enabled
Maximum number of supported VLANs without IP Address is 256
Number of DHCP Relays enabled on VLANs without IP Address is 1
DHCP relay is not configured on any port.
DHCP relay is enabled on Vlans: 1
Active: 1
Inactive:
Servers: 192.168.2.1

NETNWSW#show ip interface

IP Address I/F I/F Status Type Directed Prec Redirect Status
admin/oper Broadcast
------------------ --------- ---------- ------- --------- ---- -------- ------
192.168.2.254/24 oob UP/UP Static disable No enable Valid

so i see this, it concerns me, that there you could read no any port .