RB750 and DHCP-CLIENT (ethernet like ISP)

RouterOS Beginner Basics
1

I have a problem my routerboard 750.
Use to factory default settings, plug internet ethernet cable to ether1-gateway, my pc plug to ether2.
After that DHCP client hang the searching mode.. can’t get ip from my ISP.
I set ether1 MAC address to my authenticated address, but won’t connect.
My ISP sad, your gateways answer only unicast packet..maybe my routerboard don’t know this method.
I just upgraded 4.5 (fixed DHCP client compatibility with some DHCP servers), but problem persist.

Has anybody got any idea?

2

there is no such thing as unicast dhcp packet. you should enable sniffer on the public port, and capture what you receive from the DHCP server. maybe there is some issue with the ISP.

even if the problem is in the software, we would be able to help.

You can download and install Wireshark, and then enable sniffer like this:
http://wiki.mikrotik.com/wiki/Ethereal/Wireshark

3

Did you set up the dhcp client on that interface? They don’t come default with dhcp client. set on any interface.
/ip dhcp-client
add interface=ether1 add-default-route=yes use-peer-dns=yes

4

actually, the RB7XX do come with a DHCP client enabled on the first port …

5

You mean ROS 4.x, correct? Why would one device have dhcp client set and the rest not?

6

all of RB750 have DHCP client enabled on port one. No exceptions.

Maybe you clicked on “clear config” upon first startup when it asked you if you want to keep the default config?

7

Hi normis.
So I get a RB7xx. I set up a static ip and route in “/ip address” and “/ip route” on ether1, not knowing dhcp client is also active on ether1. Which has priority, static or dhcp? Or do I end up with 2 ips (one static and one dynamic) assigned to ether1?

8

IP addresses have no priority, there is no problem with two IPs on the same interface

However, there should be no static IP on your ether1. Maybe your distributor reconfigures your routers?

Try “System reset” and see what you get then. Also ask your distributor. Look at the grey cardboard box your RB750 came in, it has instructions on the bottom. These instructions are written based on the fact that there is a DHCP client and a DHCP server preconfigured.

9

I have no RB7xx devices yet. So the RB7xx uses dhcp client on ether1 instead of the static 192.168.88.1(?) ip as default?
No complaint here. Actually, I like the dhcp client setup by default better. I am just curious why the difference in default setups between the RB7xx devices and the rest.

10

RB700 series devices are more SOHO and end user targeted, so we made it easier to use. There is a DHCP client on the first port, a bridge with the other ports, and a DHCP server on the bridge. There is also a masquerade rule, so you can simply plug in your PCs, your ISP uplink, and all will work.

RB700 series are currently the only exception to the default config.

11

I checked: Default configuration is enabled
I tried change DHCP client option (use peer DNS, use peer NTP), but dhcp client Parameter Request List always contain: 6=Domain Name Server, 42=Network Tme Protocol Servers)

Wireshark capture filtered Bootstrap: contain only DHCP Discovery

Bootstrap Protocol
Message type: Boot Request
Hardwer type: Ethernet
Hardwer address length: 6
Hops: 0
Transaction ID: (forexample: 0x097b421f)
Second elapsed: 14:
Bootp flags: 0x8000 (Broadcast)
1… … … … = Broadcast flag: Broadcast
.000 0000 0000 0000 = Reserved flags: 0x0000
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: AsustekC_a5:34:ac (00:1e:8c:a5:34:ac) (I set ethernet interface mac-address for my ISP)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP Discover
Option: (53) DHCP Message Type
Length: 1
Value: 01
Option: (t=61,l=7) Client identifier
Option: (61) Client identifier
Length: 7
Value: 01001E8CA534AC
Hardware type: Ethernet
Client MAC address: AsustekC_a5:34:ac (00:1e:8c:a5:34:ac)
Option: (t=55,l=6) Parameter Request List
Option: (55) Parameter Request List
Length: 6
Value: 01790321062A
1 = Subnet Mask
121 = Classless Static route
3 = Router
33 = Static route
6 = Domain Name Server
42 = Network Time Protocol Servers
Option: (t=12,l=8) Host Name = “MikroTik”
Option: (12) Host Name
Length: 8
Value: 4D696B726F54696B
End Option
Padding

No other error or message.
My ISP of course sad this is my router fault.

12

it would be great if you could take this router to some friend with another ISP and check how it works there

13

Hi Pollux,
What does this mean? Why did you change the mac address?

14

Because my ISP authenticate our account by mac address, my router can connect only by specific mac.
This mac was set the prevous router, this is registered my isp system.

15

maybe tell the ISP to change the MAC in the system, and then use the RB750 native MAC? That should be an easy procedure, and would make sure that this setting is not the cause of the problem

16

Just a thought…
I don’t know how you connect, but my ISP’s cablemodems DO NOT like any mac changing. Any time I change a device, I MUST power down my cablemodem for several seconds before it will talk to the new device.

17

There is no cabel modem, just ethernet cable.

I askd my ISP to register RB native MAC in his system (only one phone call), after that, i used nativ MAC address, but the result was same.

My ISP won’t change any configuration, he tell us his configurations is working every other router.

Maybe we must bay another router. Thany you for your help.

18

That would be a limit put there by your ISP.

Source : I manage a wireless DOCSIS network.

19

I have my RB750 setup at home. Currently I am testing 3.5GHz WiMax and the first ethernet is port has a DHCP client. Did you try cloning the MAC ?