NX-OS 'guestshell' 'start dhcpd Failed to get D-Bus connection'

[TheGoob]

Hello

Was wondering if anyone off chance had an idea about this. Was setting up a DHCPD Server on my NX-OS and followed a guide https://github.com/ndelecro/nx-os-programmability/tree/master/Guest_Shell/PXE_Server but when I get to the part to

 systemctl start dhcpd

I get

Failed to get D-Bus connection: No such file or directory

I try reinstalling DBUS [No idea what it even is] and it says

[root@guestshell admin]# yum install dbus
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirrors.oit.uci.edu
 * extras: mirrors.raystedman.org
 * updates: centos-distro.1gservers.com
Package 1:dbus-1.10.24-15.el7.x86_64 already installed and latest version
Nothing to do

Wondering/hoping someone has had same error or can direct me?

[balaji.bandi]

what nexus model and nexus code running on it.

check is the system bus running :

systemctl status --all dbus.socket

Also try # systemctl daemon-reload

[TheGoob]

Weird, last night when I entered the dhcp start command, it had an error; this morning..

systemctl status --all dbus.socket
● dbus.socket - D-Bus System Message Bus Socket
   Loaded: loaded (/usr/lib/systemd/system/dbus.socket; static; vendor preset: disabled)
   Active: active (running) since Sun 2024-01-14 05:36:29 UTC; 9h ago
   Listen: /run/dbus/system_bus_socket (Stream)
[root@ceyea admin]# systemctl daemon-reload
[root@ceyea admin]# systemctl start dhcpd

Well, I guess that is that   Thank you.

[balaji.bandi · Accepted solution]

[root@ceyea admin]# systemctl daemon-reload
[root@ceyea admin]# systemctl start dhcpd

Glad that suggestion works and you able to move forward to configure DHCP Server.

 but man alive it is soooo slow and even times out.

This is different issue, slow means browsing - looks for me everything relies on DNS Resolution. nothing to do with Guestshell and DHCP - that docker only offer you DHCP Service.

Rest connecting to internet is your Routing decision. and DNS resolution.

how is your topology looks like - if you not going via nexus do you have better connectivity ?

[TheGoob]

Well now everything seems to half work.

Alright... On NEXUS, I can ping

switch(config)# ping 8.8.8.8 source 192.168.3.1
PING 8.8.8.8 (8.8.8.8) from 192.168.3.1: 56 data bytes
64 bytes from 8.8.8.8: icmp_seq=0 ttl=118 time=25.084 ms
64 bytes from 8.8.8.8: icmp_seq=1 ttl=118 time=25.198 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=118 time=25.917 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=118 time=24.921 ms
64 bytes from 8.8.8.8: icmp_seq=4 ttl=118 time=25.649 ms

From the guestshell

[admin@dhcpd ~]$ ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=119 time=24.5 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=119 time=25.7 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=119 time=25.4 ms
64 bytes from 8.8.8.8: icmp_seq=4 ttl=119 time=25.4 ms
64 bytes from 8.8.8.8: icmp_seq=5 ttl=120 time=25.3 ms
64 bytes from 8.8.8.8: icmp_seq=6 ttl=120 time=26.0 ms

Now, inside ANY host that connects to the LAN via guestshell dhcp, I can ping any other LAN but can not Ping outside the Nexus..

So foe example on Windows PC, that connects and obtains all valid info from dhcp server.

C:\Users\mjmal>ping 8.8.8.8

Pinging 8.8.8.8 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

Ping statistics for 8.8.8.8:
    Packets: Sent = 4, Received = 0, Lost = 4 (100% loss)

It seems as if the guestshell has some sort of firewall or block for outgoing.

Below are my configs.

This is my guestshell dhcpd.conf

default-lease-time 600;
max-lease-time 7200;
authoritive;
subnet 192.168.1.0 netmask 255.255.255.0 {
        option broadcast-address 192.168.1.255;
        option routers 192.168.1.1;
        range dynamic-bootp 192.168.1.3 192.168.1.254;
        option domain-name-servers 8.8.8.8;
}
subnet 192.168.2.0  netmask 255.255.255.0 {
        option broadcast-address 192.168.2.255;
        option routers 192.168.2.1;
        range dynamic-bootp 192.168.2.3 192.168.2.254;
        option domain-name-servers 8.8.8.8;
}
subnet 192.168.3.0  netmask 255.255.255.0 {
        option broadcast-address 192.168.3.255;
        option routers 192.168.3.1;
        range dynamic-bootp 192.168.3.3 192.168.3.254;
        option domain-name-servers 8.8.8.8;
}
subnet 192.168.4.0  netmask 255.255.255.0 {
        option broadcast-address 192.168.4.255;
        option routers 192.168.4.1;
        range dynamic-bootp 192.168.4.3 192.168.4.254;
        option domain-name-servers 8.8.8.8;
}
subnet 192.168.6.0  netmask 255.255.255.0 {
        option broadcast-address 192.168.6.255;
        option routers 192.168.6.1;
        range dynamic-bootp 192.168.6.3 192.168.6.254;
        option domain-name-servers 8.8.8.8;
}

This is my ip route in guestshell

[admin@dhcpd ~]$ ip route
default proto static metric 51
        nexthop via 192.168.1.2 dev Vlan2 weight 1 onlink
        nexthop via 192.168.2.2 dev Vlan3 weight 1 onlink
        nexthop via 192.168.3.2 dev Vlan4 weight 1 onlink
        nexthop via 192.168.4.2 dev Vlan5 weight 1 onlink
        nexthop via 192.168.6.2 dev Vlan6 weight 1 onlink
127.1.0.0/16 dev veobc proto kernel scope link src 127.1.1.1
127.1.2.0/24 dev veobc proto kernel scope link src 127.1.2.1
192.168.1.0/24 dev Vlan2 proto 98 scope link
192.168.1.2 dev Vlan2 proto 98 scope link metric 51
192.168.1.180 dev Vlan2 proto 98 scope link metric 51
192.168.2.0/24 dev Vlan3 proto 98 scope link
192.168.2.2 dev Vlan3 proto 98 scope link metric 51
192.168.2.181 dev Vlan3 proto 98 scope link metric 51
192.168.3.0/24 dev Vlan4 proto 98 scope link
192.168.3.2 dev Vlan4 proto 98 scope link metric 51
192.168.3.3 dev Vlan4 proto 98 scope link metric 51
192.168.4.0/24 dev Vlan5 proto 98 scope link
192.168.4.2 dev Vlan5 proto 98 scope link metric 51
192.168.4.115 dev Vlan5 proto 98 scope link metric 51
192.168.4.116 dev Vlan5 proto 98 scope link metric 51
192.168.4.119 dev Vlan5 proto 98 scope link metric 51
192.168.4.120 dev Vlan5 proto 98 scope link metric 51
192.168.4.178 dev Vlan5 proto 98 scope link metric 51
192.168.6.0/24 dev Vlan6 proto 98 scope link
192.168.6.2 dev Vlan6 proto 98 scope link metric 51
192.168.6.102 dev Vlan6 proto 98 scope link metric 51
192.168.6.177 dev Vlan6 proto 98 scope link metric 51

This is my Nexus configuration;

ip route 0.0.0.0/0 192.168.1.2
ip route 0.0.0.0/0 192.168.2.2
ip route 0.0.0.0/0 192.168.3.2
ip route 0.0.0.0/0 192.168.4.2
ip route 0.0.0.0/0 192.168.6.2
vlan 1-6

service dhcp
ip dhcp relay

interface Vlan1

interface Vlan2
  no shutdown
  ip address 192.168.1.1/24
  ip dhcp relay address 192.168.1.1

interface Vlan3
  no shutdown
  ip address 192.168.2.1/24
  ip dhcp relay address 192.168.2.1

interface Vlan4
  no shutdown
  ip address 192.168.3.1/24
  ip dhcp relay address 192.168.3.1

interface Vlan5
  no shutdown
  ip address 192.168.4.1/24
  ip dhcp relay address 192.168.4.1

interface Vlan6
  no shutdown
  ip address 192.168.6.1/24
  ip dhcp relay address 192.168.6.1

I really do not see how it can not ping "through" the DHCP Server, unless I have a misconfig...

[TheGoob]

What are your thoughts on the data above?

[balaji.bandi]

my thoughts already shared here - you need to provide more information to assists you.