Hello.
First of all, I am new to RouterOS.
Thanks to everyone who will take time to read my post.
I have a question regarding DHCP-server and NTP.
Before posting I searched on the forums and on the web, but I found only this similar post:
http://forum.mikrotik.com/t/disable-announcing-ntp-server-in-dhcp/92544/1
unfortunately without answers.
I recently replaced my home router with a CRS109-8G-1S-2HnD running version 6.33.2 (stable).
It serves as a DHCP server for my clients.
I also configured it as a client to an NTP server I run in my network:
The configuration is:
CRS109 → 192.168.25.1 (MikroTik router)
NTPserver → 192.168.25.62 (my NTP server)
[admin@MikroTik] > /system ntp client print
enabled: yes
primary-ntp: 192.168.25.62
server-dns-names:
mode: unicast
poll-interval: 15m
active-server: 192.168.25.62
last-update-from: 192.168.25.62
last-update-before: 6m6s790ms
last-adjustment: 5ms925us
[admin@MikroTik] >
So far, so well.
But I have noticed that it provides to the clients the address of its NTP server, even though (I believe) it is not configured to do this (no NTP server, nor any option configured in the DHCP-server):
[admin@MikroTik] > /ip dhcp-server network print detail
0 ;;; default configuration
address=192.168.25.0/24 gateway=192.168.25.1 netmask=24 dns-server=192.168.25.1 wins-server="" ntp-server="" caps-manager="" dhcp-option=""
[admin@MikroTik] >
[admin@MikroTik] > /ip dhcp-server option print
# NAME CODE VALUE RAW-VALUE
[admin@MikroTik] >
I have verified that on all of my clients (all are linux boxes) that get the address from the DHCP, they receive the NTP server as well.
I have tested a virtual machine with CHR (updated to 6.33.2 stable), and captured some packets.
It has the mac address 08:00:27:a5:a4:50, and receives the address 192.168.25.253
See below the discover, request and ack packets from the DHCP conversation.
My doubt is: since the DHCP server is not configured to send the NTP information to the clients, is it correct that the NTP server is sent to the client?
Or is this a wrong configuration on my side?
Thanks,
Andrea
## DHCP CONVERSATION ##
## DISCOVER ##
Frame 17181: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits)
Ethernet II, Src: xx:xx:xx:xx:xx:xx (xx:xx:xx:xx:xx:xx), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol Version 4, Src: 0.0.0.0 (0.0.0.0), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: 68 (68), Dst Port: 67 (67)
Bootstrap Protocol (Discover)
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x1ac1b8ab
Seconds elapsed: 0
Bootp flags: 0x8000, Broadcast flag (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: 08:00:27:a5:a4:50 (08:00:27:a5:a4:50)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (Discover)
Length: 1
DHCP: Discover (1)
Option: (55) Parameter Request List
Length: 7
Parameter Request List Item: (1) Subnet Mask
Parameter Request List Item: (121) Classless Static Route
Parameter Request List Item: (3) Router
Parameter Request List Item: (33) Static Route
Parameter Request List Item: (6) Domain Name Server
Parameter Request List Item: (42) Network Time Protocol Servers
Parameter Request List Item: (138) CAPWAP Access Controllers
Option: (255) End
Option End: 255
Padding: 000000000000000000000000000000000000000000000000...
## REQUEST ##
Frame 17186: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits)
Ethernet II, Src: xx:xx:xx:xx:xx:xx (xx:xx:xx:xx:xx:xx), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol Version 4, Src: 0.0.0.0 (0.0.0.0), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: 68 (68), Dst Port: 67 (67)
Bootstrap Protocol (Request)
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x1ac1b8ab
Seconds elapsed: 0
Bootp flags: 0x8000, Broadcast flag (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: 08:00:27:a5:a4:50 (08:00:27:a5:a4:50)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (Request)
Length: 1
DHCP: Request (3)
Option: (54) DHCP Server Identifier
Length: 4
DHCP Server Identifier: 192.168.25.1 (192.168.25.1)
Option: (50) Requested IP Address
Length: 4
Requested IP Address: 192.168.25.253 (192.168.25.253)
Option: (55) Parameter Request List
Length: 7
Parameter Request List Item: (1) Subnet Mask
Parameter Request List Item: (121) Classless Static Route
Parameter Request List Item: (3) Router
Parameter Request List Item: (33) Static Route
Parameter Request List Item: (6) Domain Name Server
Parameter Request List Item: (42) Network Time Protocol Servers
Parameter Request List Item: (138) CAPWAP Access Controllers
Option: (255) End
Option End: 255
Padding: 000000000000000000000000000000000000000000000000...
## ACK ##
Frame 17188: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits)
Ethernet II, Src: Routerbo_xx:xx:xx (e4:8d:8c:xx:xx:xx), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol Version 4, Src: 192.168.25.1 (192.168.25.1), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: 67 (67), Dst Port: 68 (68)
Bootstrap Protocol (ACK)
Message type: Boot Reply (2)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x1ac1b8ab
Seconds elapsed: 0
Bootp flags: 0x8000, Broadcast flag (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: 192.168.25.253 (192.168.25.253)
Next server IP address: 192.168.25.1 (192.168.25.1)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: 08:00:27:a5:a4:50 (08:00:27:a5:a4:50)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (ACK)
Length: 1
DHCP: ACK (5)
Option: (54) DHCP Server Identifier
Length: 4
DHCP Server Identifier: 192.168.25.1 (192.168.25.1)
Option: (51) IP Address Lease Time
Length: 4
IP Address Lease Time: (43200s) 12 hours
Option: (1) Subnet Mask
Length: 4
Subnet Mask: 255.255.255.0 (255.255.255.0)
Option: (3) Router
Length: 4
Router: 192.168.25.1 (192.168.25.1)
Option: (6) Domain Name Server
Length: 4
Domain Name Server: 192.168.25.1 (192.168.25.1)
Option: (42) Network Time Protocol Servers
Length: 4
Network Time Protocol Server: 192.168.25.62 (192.168.25.62)
Option: (255) End
Option End: 255
Padding: 0000000000000000000000000000000000000000