Community discussions

MikroTik App
 
peper
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 56
Joined: Tue Sep 11, 2012 8:45 pm

RB4011, 260GS and SFP link

Fri Jan 15, 2021 11:13 pm

Hello!

Had some issues with connecting my RB4011iGS+ and 260GS/260GSP switches via SFP direct attach cable so want to share experience for others who can have the same. :)
1) I was not very attentive when reading this https://wiki.mikrotik.com/wiki/MikroTik ... lity_table from smartphone and missed that S+DA0001 (https://mikrotik.com/product/SplusDA0001, already discontinued, but still sold a lot) is not compatible with 4011. So I bough it and have to return after it failed to work.
2) Newer version XS+DA0001 (https://mikrotik.com/product/xs_da0001) is compatible with both 4011 and 260. And is still rather cheap variant to connect those two.
3) You have to manually set 4011 SFP+ port to 1G speed as described here https://wiki.mikrotik.com/wiki/MikroTik ... ansceivers
It won't work with autonegotiation.
4) On 260GS/260GSP side it works automatically without any hassle.

Regards,
Petr
 
mada3k
Long time Member
Long time Member
Posts: 687
Joined: Mon Jul 13, 2015 10:53 am
Location: Sweden

Re: RB4011, 260GS and SFP link

Sat Jan 16, 2021 11:24 am

Generally SFP+ is not compatible in SFP devices. I'm amazed that it works. But yes, probably only in manual speed settings.
 
peper
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 56
Joined: Tue Sep 11, 2012 8:45 pm

Re: RB4011, 260GS and SFP link

Sat Jan 16, 2021 2:00 pm

Generally SFP+ is not compatible in SFP devices. I'm amazed that it works. But yes, probably only in manual speed settings.
Descriptions for https://mikrotik.com/product/xs_da0001 says that
This is highly cost-effective way to connect two SFP/SFP+/SFP28 devices (for example two units of our new CCR2004-1G-12S+2XS) for very short distances, within racks and across adjacent racks.
The only "contra" here is that I was connecting SFP (260GS) and SFP+ (4011) devices.
Maybe I misunderstood description and it should not work, but it works (at 1Gb speed). :)
 
User avatar
mkx
Forum Guru
Forum Guru
Posts: 11433
Joined: Thu Mar 03, 2016 10:23 pm

Re: RB4011, 260GS and SFP link  [SOLVED]

Sat Jan 16, 2021 4:46 pm

XS-DA00001 supports 1Gbps (I'd be surprised if it wasn't as it's a passive DAC). What only matters is if devices on both ends support same rate at their SFP (plain/+/28) cages. (And whether they support passive DAC at all). SFP cage rate is usually not auto-negotiated ... it can adjust if active equipment (SFP modules) support DDC (most do, but not all) and device and module understand each other (DDC is completely unrelated to "main" SFP rate). Since passive DAC doesn't have active elements to speak DDC, it's down to manual rate selection (I guess default is SFP's maximum rate, hence need to down-rate SFP+ in 4011 to default rate of SFP in 260GS).
 
peper
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 56
Joined: Tue Sep 11, 2012 8:45 pm

Re: RB4011, 260GS and SFP link

Sat Jan 16, 2021 6:59 pm

XS-DA00001 supports 1Gbps (I'd be surprised if it wasn't as it's a passive DAC). What only matters is if devices on both ends support same rate at their SFP (plain/+/28) cages. (And whether they support passive DAC at all). SFP cage rate is usually not auto-negotiated ... it can adjust if active equipment (SFP modules) support DDC (most do, but not all) and device and module understand each other (DDC is completely unrelated to "main" SFP rate). Since passive DAC doesn't have active elements to speak DDC, it's down to manual rate selection (I guess default is SFP's maximum rate, hence need to down-rate SFP+ in 4011 to default rate of SFP in 260GS).
Thank you! That's exactly what my experience was, but while I was not aware of this in advance, have to find it myself (after initial frustration). Hope this will help others with same or similar set of hardware. Overall XS-DA0001 seems to be very nice (and cost effective) for home application.
 
User avatar
dwnldr
newbie
Posts: 46
Joined: Sat Apr 11, 2020 10:06 am
Location: Slovakia

Re: RB4011, 260GS and SFP link

Wed Dec 06, 2023 10:50 am

Dear community !

I would like to kindly ask you for your opinions and ideas, since im struggling to restore connection between two upper mentioned devices.

Just to repeat :
RB4011+260GS wired with xs-da00001. All devices are brand new, with default configs, most recent ROS 7.12.x and SWOS 2.13.
The link speed is set manually to 1Gbit on RB4011, connection is established and i am able to connect and operate 260GS (through RB4011). BUT, only till restart of router (RB4011). After boot is "some" connection between two devices established, i see transmitting packets, datas, cable blink test reports "link ok", everythink looks really ok, but no IP address is assigned for 260GS and is also not visible in neighbours. ONLY TILL i disable/enable manually in RB4011 the SFP port for a second. After this workaround RB260 immediately appears in router (RB4011) DHCP Lease list, neighbours and the connection is again "as it should be".

Guys, have you please any experience, workaround for this ? Maybe a software bug ? I went through all compatible Link speed settings, SFP settings one-by-one to check how it behaves after restart, bud sadly the result was the same.

EDIT: the combination RB4011+CSS610-8G (sfp+ to sfp+ with the same RB4011 and same xs-da00001 works without this issue)

Thank you very much !

Who is online

Users browsing this forum: Michiganbroadband and 29 guests