On 08/22/2018 06:00 PM, ToddAndMargo wrote:
On 08/22/2018 04:37 PM, Ed Greshko wrote:
> On 08/23/18 06:47, ToddAndMargo wrote:
>> Hi All,
>>
>> My iptables firewall ported from RHEL won't connect to ftp sites
>> and throws this error (written by me years ago):
>>
>>
>> WARNING: active FTP rules have been selected but one or
>> more necessary modules have not been detected
>>
>> In /etc/sysconfig/iptables-config, you must add ip_nat_ftp
>> and ip_conntrack_ftp to IPTABLES_MODULES. Delimiter is a
>> space. For example:
>> IPTABLES_MODULES=ip_nat_ftp ip_conntrack_ftp
>>
>> To load changes, use:
>> # /etc/rc.d/init.d/iptables restart
>> # systemctl restart iptables
>>
>> To check if modules are loaded, use
>> lsmod
>>
>>
>> 1) is Fedora doing FTP differently in iptables?
>>
>> 2) where do I find
>> ip_nat_ftp
>> ip_conntrack_ftp
>> now a days?
>>
>
> I can't locate my notes at the moment. But I believe the way things
> are done in the
> netfilter framework has changed.
>
> If memory servers me the nf_conntrack_ipv4 will load, as needed, the
> necessary
> "helper". I use the standard firewall and these modules are loaded.
>
> xt_conntrack 16384 21
> nf_conntrack_ipv6 16384 12
> nf_defrag_ipv6 20480 1 nf_conntrack_ipv6
> nf_conntrack_ipv4 16384 11
> nf_defrag_ipv4 16384 1 nf_conntrack_ipv4
> nf_conntrack 147456 6
> xt_conntrack,nf_conntrack_ipv6,nf_conntrack_ipv4,nf_nat,nf_nat_ipv6,nf_nat_ipv4
>
> libcrc32c 16384 2 nf_conntrack,nf_nat
>
> and ftp works fine.
>
> ip_nat_ftp does not exist on my system. But I do have nf_conntrack_ftp.
I see nf_conntrack_ftp inserted
# lsmod | grep nf_conntrack_ftp
nf_conntrack_ftp 20480 1 nf_nat_ftp
nf_conntrack 147456 9
xt_conntrack,nf_nat_masquerade_ipv4,nf_conntrack_ipv4,nf_nat,nf_nat_ftp,ipt_MASQUERADE,nf_nat_ipv4,xt_helper,nf_conntrack_ftp
But it is not following the high ports that ftp uses:
Aug 22 16:12:09 rn6 kernel: dsl-out Everything Else IN= OUT=eno2
SRC=192.168.xxx.yyy DST=208.106.xxx.yyy LEN=60 TOS=0x00 PREC=0x00 TTL=64
ID=25991 DF PROTO=TCP SPT=59698 DPT=21023 WINDOW=29200 RES=0x00 SYN URGP=0
Perhaps I missed this, but are you trying to set up an FTP _server_ on
your machine or using it as an FTP client? The firewall rules for an
FTP server would be significantly different--especially if you wish to
provide both passive and normal FTP operations.
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