Mikrotik problem: user3799089

user3799089

9:56 AM

hi

Mike Pennington

hello

user3799089

thank You for Your attention and spending some time to resolve my problem

Mike Pennington

When I changed default gateway from 1.1.1.9 to 1.1.1.10 I lost connectivity to the Internet from my MTR and whole LAN. SO If I want to use 1.1.1.9 IP addres I have to leave 1.1.1.9 in NAT table and change in routing table default gateway to 1.1.1.10 ? I`m I correct ? — user3799089 6 mins ago

user3799089

yes

Mike Pennington

You cannot use 1.1.1.9 as a default gateway and an external IP address on the Mikrotik

user3799089

9:58 AM

external addres of MTR is 1.1.1.10

it has to be like this

Mike Pennington

so... previously the remote VPN side of things worked when you had 1.1.1.9/30 on ISP-A's modem, and 1.1.1.10/30 on the Mikrotik, correct?

user3799089

1.1.1.9 is an ISP modem interface IP addr

hmm its more complicated

my company network from Internat has address 1.1.1.9

so Internet sees my IP like 1.1.1.9 but it is ISP modem address

my mikrotik ip add is 1.1.1.10

so ...

Mike Pennington

are you on a DOCSIS modem?

user3799089

I can set two addresses .9 and .10

before when I use in mikrotik configuration .10 I could connect from my laptop to the my NAS without ISP modem

it was only test that do his modem some port cutting or smoething like that

but earlier in our previous HQ we use IP add what whas vissible from Internet

in this case it is .9 addres

so I changed MikroTik configuration

Mike Pennington

can the mikrotik ping 4.2.2.2 now?

user3799089

10:02 AM

and since that I can not connect to my LAN from ISP siede

and I receive that same error aht our remotes

Mike Pennington

can the mikrotik ping 4.2.2.2 now?

user3799089

what is this add 4.2.2.2.2 ?

Mike Pennington

It's a famous public DNS IP address

everyone on the internet should be able to ping it

user3799089

oh level3 DNS

Mike Pennington

if your routing table is correct

user3799089

10:04 AM

yea I can ping it from my laptop connected to the mikroTik

and from MikroTik directly

Mike Pennington

so now, what is the IP on the Mikrotik and on the ISP-A modem?

user3799089

ISP modem interface -> .9

our MikroTik interface -> /10

I mean .10

Mike Pennington

ok... so are hoping to swap the modem's address with the Mikrotik's address?

user3799089

negative

I`m not able to configure ISP device

I think it is truely their telephone exchange address

Mike Pennington

if 1.1.1.9/30 is on the ISP-A modem, and you cannot configure the ISP-A modem, then you cannot change the IP address on the Mikrotik to 1.1.1.9...

user3799089

10:08 AM

yes I know

the network pool is small just two useble addresses

.9 for them

and .10 for us

and boradcast address

.11

.12 is network addres another network

Mike Pennington

ok, so why are you using 1.1.1.9 in your NAT table?

that belongs to the ISP, and you cannot use it

user3799089

so gateway .9 and NAT .10

Mike Pennington

yes

as I understand the configuration

user3799089

ok I see

I change it to use .9 addres which is seen from the Internet

Mike Pennington

It sounds like ISP-A's modem is doing some kind of NAT too

they are NAT-ing all your traffic to 1.1.1.9, so if you want them to remove the NAT, you'll have to work that out with them

user3799089

10:12 AM

I`m trying

Mike Pennington

can the company B laptop ping 1.1.1.10?

user3799089

they told me that they disabled all nat`s and firewalls etc.

but I dont beleve them

I dont know

Mike Pennington

ok, it's a relatively important point

I'm assuming your real addresses on the Mikrotik is a public IP address, correct?

user3799089

I will ask

no

before our public address was with .9

but I cheked now

and today is .10

:/

Mike Pennington

when I say "public ip address", I mean you're not using any RFC1918 address space on the Mikrotik's ISP-A modem side... correct?

user3799089

10:19 AM

no

I mean yes

we dont use any private pools od IP addresses

Mike Pennington

good

user3799089

*of

thats why I use 1.1.1.n in my example

to show that this is public add

when I made some port tests from webs

Mike Pennington

ok, so we just need to ensure that Company B can ping 1.1.1.10, and then use that as your Mikrotik NAT addressing

user3799089

I saw our 1723 port

so it looks like they dont cut it

ow ok I will let them do that

Mike Pennington

now, as for other specifics of configuring PPTP on the Mikrotik, I can't really assist since it isn't a platform I use on a regular basis

user3799089

10:23 AM

ok, no problem

I will handle it

the main question is does ISP cut anythong

so I have to go for a meeting

thank You for Your time

I realy apreciate it :)

how Can I point Your help at network exchange forum ?

Mike Pennington

You mean mark my answer as correct?

user3799089

I think yes

I changed dynDNS records

and NAT rules

adn they have acces over TTPT tunels :)

Mike Pennington

Perfect

You can mark the answer as accepted by clicking the grey check mark on the left side of my answer score

584

A: How does accepting an answer work?

Accepting Answers: How does it work? Accepting an answer is important as it both rewards posters for solving your problem and informs others that your issue is resolved. You may select any answer on questions you asked as the "accepted" answer. Only one answer at a time can be the 'accepted' a...

user3799089

2:08 PM

now I`m online

ok, I will

:)

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Mikrotik problem: user3799089