Firewall behaviour is strange on one of my systems

[Rick Stevens]

On 10/28/2015 03:52 AM, antonio montagnani wrote:
> I am using a desktop where I have connected a printer: if I enable the
> firewall I can connect by IP numbers and print if printer is
> nameofprinter at IPof desktop (the same with vinagre, i can connect by IP
> numbers and not by names): the only way to print (and connect by names
> in vinagre, and share Public Files) is to have firewall stopped.
>
> This is my firewall configuration:
>
> FedoraWorkstation (default, active)
>    interfaces: p19p1
>    sources:
>    services: dhcpv6-client dns ipp ipp-client mdns samba-client ssh
>    ports: 1025-65535/udp 1025-65535/tcp
>    masquerade: no
>    forward-ports:
>    icmp-blocks:
>    rich rules:
>
>
> any help??? Tnx

You have a DNS resolution issue. With the firewall enabled, as root,
try:

	# iptables -L -n | grep :53

and make sure you see lines like:

	ACCEPT  udp  --  0.0.0.0/0    0.0.0.0/0            udp dpt:53
	ACCEPT  tcp  --  0.0.0.0/0    0.0.0.0/0            tcp dpt:53

to ensure you can do DNS. These don't normally show up under the
firewall GUI. If they are NOT open on your machine, then open them in
the firewall GUI and reload the firewall.

Also make sure avahi-daemon and dnsmasq are running. Avahi-daemon is
generally run via

	# systemctl start avahi-daemon.service

dnsmasq is usually started by the libvirtd service if you have
virtualization installed. If not, it can be started via

	# systemctl start dnsmasq.service

If you've had to start either, then also

	# systemctl enable <name-of-service>

to make sure they start on the next reboot as well.
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- Rick Stevens, Systems Engineer, AllDigital    ricks at alldigital.com -
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