I have two pppoe access points on a fiber optic modem. I plan to connect and share these two ports with a CRS326-24G-2S+. What is the best way to proceed?

Do I do this with bonding, or should I connect the lines with ppc load balancing. In any case I want to be able to use this at the same time. So e.g. surf on one line and provide access to a file server on the other line etc.

Rosi

two pppoe access points , you mean two Access Concentrator ? one main,one backup

There are two accounts connected to 1 (one) modem which is connected to an optical fibre. At port 1 (CAT45) I get an IP with the access data user/password and at port 2 (CAT 45) I get another IP with different access data user/password. I can use both accesses separately.

I simply imagined that it should be possible to use both ports together. On the one hand as backup and on the other hand account 1 for downloads and account 2 for access from the internet to a file server (Nextcloud etc.)

Am I wrong here? Is that not possible?

You can use multiple uplinks, but the strategies of their use you can choose from depend on their properties. Bonding can only be used to group together L2-transparent interfaces, which is not the case of PPPoE.

If I get you right, the PPPoE clients are running on the modem, so on each RJ45 port, there is a DHCP server running, and each of these DHCP servers assigns IP addresses from a different private subnet?

so if I understand correctly, you have two pppoe account, through two ports on the same device (a modem?).
yes the CRS326 can be used to establish two pppoe connections and use them as you described. However, CRS326 is an exlent switch, but less of a router. Its routing capacity is limited.
looking at this
https://mikrotik.com/product/CRS326-24G ... estresults
expect 260-520 Mbps throughput as a router.

now, the how to part:
add two pppoe client on ether1 and ether2 (taking ether 2 out of the default bridge fist)
look up load balancing examples
https://wiki.mikrotik.com/wiki/Load_Balancing

edit: @sindy, you might be right, being a modem, he would get DHCP lease from it, instead of pppoe . but who knows

Thanks for the info.
Then I will probably buy a RB4011iGS+RM and use it for routing.

L2 bridge is difficult to accomplish since it needs interoperability form the provider and must be the same provider. PPC is the best and obvious way to go and RB4011 is good choice. It doesn't matter in this case if interfaces are pppoe clients or ethernet interfaces. Usually you should group wan and lan interfaces into groups to minimise rules in firewall by selecting interface groups rather than one interface in one rule.
Connections can be split evenly like 1:1 or at different ratio like 2:1, 3:2 etc. More than 2 upstream providers can be also load balanced.
Mangle rules for inbound connections are necessary to reply through the same interface in input chain.
For dst nat to work properly also mangle rules from wan interface to local lan in forward chain are necessary. Sticky connections so when one interface goes down connections don't go through the other gateway.
Most srvices now can make use of multiple connections so can make use of both upstream providers simultaneously. Only some services like web portals or bank portals don't like the ip change from a provider to another. Will give you a warning and kick you out of the session. So its important to set connection classifier with both adressess src and dst rather than src address and src port for https connections tcp/443.

I would need your additional support.

As already mentioned, I plan to do the routing with a RB4011iGS+RM. Since I already have three CRS326-24G-2S+ as switches, I plan to use them with ROS as well. Is that ok, or does it work better with SwOS? Basically, I would also be interested to know which packets I need for the pure switch functions (incl. VLAN etc.) in ROS. I am of the opinion that I don't have to install packages I don't need or can delete them to avoid a possible source of error on my part.