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| Model name | MTU description |
| RB SXT series, RB LHG, RB LDF, PL6411-2nD, PL7411-2nD, RB711 series, wAP R-2nD, RB912R-2nD-LTm (LtAP mini), RB Metal series, RB SXT Lite series, RB Groove series, Cube Lite60, LHG Lite60 | ether1:2028 |
| RB SXT G series, RB DynaDish, wAP ac, RB QRT series, RB711G series, RB911G, RB912UAG | ether1:4076 |
| RB OmniTik series, RB750, RB750UP, RB751U-2HnD, RB951-2n | ether1:4076; ether2-ether5:2028 |
| RB OmniTik ac series, RB750GL, RB750Gr2 | ether1-ether5:4074 |
| RB mAP, RB mAP lite, RB cAP, RB wAP | ether1-ether2:2028 |
| RB750r2, RB750P-PBr2, RB750UPr2, RB941-2nD, RB951Ui/RB952Ui series | ether1-ether5:2028 |
| RB750Gr3 | ether1-ether5:2026 |
| RB751G-2HnD, RB951G-2HnD | ether1-ether5:4074 |
| RB962UiGS, RB960PGS | ether1-ether5:4074; sfp1:4076 |
| RB LHGG series | ether1:9214 |
| LHG XL 52 ac | ether1:9214; sfp1:9214 |
| RB1100Hx2, RB1100AHx2 | ether1-ether10:9498; ether11:9500; ether12-ether13:9116 |
| RB4011iGS+ series | ether1-ether10:9578; sfp-sfpplus1:9982 |
| CCR1009 series | ether1-ether4:10224; ether5-ether8:10226; sfp1:10226; sfp-sfpplus1:10226 |
| CCR1016 series | ether1-ether12:10226; sfp1-sfp12:10226; sfp-sfpplus1:10226 |
| CCR1036 series | ether1-ether12:10226; sfp1-sfp4:10226; sfp-sfpplus1-sfp-sfpplus2:10226 |
| CCR1072 series | ether1:9116; sfp-sfpplus1-sfp-sfpplus8:10226 |
| CCR2004-1G-12S+2XS | ether1:9586; sfp-sfpplus1-sfp-sfpplus12:9578; sfp28-1 - sfp28-2:9578 |
| CCR2004-16G-2S+ | ether1-ether16:9582; sfp-sfpplus1-sfp-sfpplus2:9586 |
| CCR2116-12G-4S+ | ether1-ether12:9570; ether13:9586; sfp-sfpplus1-sfp-sfpplus4:9570 |
| CCR2216-1G-12XS-2XQ | ether1:9586; sfp28-1 - sfp28-12:9570; qsfp28-1-1 - qsfp28-2-4:9570 |
| CRS109-8G-1S | ether1-ether8:4064; sfp1:4064 |
| CRS125-24G-1S | ether1-ether24:4064; sfp1:4064 |
| CRS112-8G-4S, CRS112-8P-4S | ether1-ether8:9204; sfp9-sfp12:9204 |
| CRS106-1C-5S | sfp1-sfp5:9204; combo1:9204 |
| CRS210-8G-2S+ | ether1-ether8:9204; sfp-sfpplus1:9204; sfpplus2:9204 |
| CRS212-1G-10S-1S+ | ether1:9204; sfp1-sfp10:9204; sfpplus1:9204 |
| CRS226-24G-2S+ | ether1-ether24:9204; sfp-sfpplus1:9204; sfpplus2:9204 |
| CRS326-24G-2S+, CSS326-24G-2S+ | ether1-ether24:10218; sfp-sfpplus1:10218; sfpplus2:10218 |
| CRS317-1G-16S+ | ether1:10218; sfp-sfpplus1-sfp-sfpplus16:10218 |
| CRS328-24P-4S+ | ether1-ether24:10218; sfp-sfpplus1-sfp-sfpplus4:10218 |
| CRS328-4C-20S-4S+ | combo1-combo4:10218; sfp1-sfp20:10218; sfp-sfpplus1-sfp-sfpplus4:10218 |
| CRS305-1G-4S+ | ether1:10218; sfp-sfpplus1-sfp-sfpplus4:10218 |
| CRS309-1G-8S+ | ether1:10218; sfp-sfpplus1-sfp-sfpplus8:10218 |
| netFiber 9/IN (CRS310-1G-5S-4S+) | sfp1-sfp5:10218; sfp-sfpplus1-sfp-sfpplus4:10218 |
| CRS310-8G+2S+IN | ether1-ether8:10218; sfp-sfpplus1-sfp-sfpplus2:10218 |
| CRS312-4C+8XG | combo1-combo4:10218; ether1-ether8:10218; ether9:2028 |
| netPower 15FR (CRS318-1Fi-15Fr-2S) | ether1-ether16:10218; sfp1-sfp2:10218 |
| netPower 16P (CRS318-16P-2S+) | ether1-ether16:10218; sfp-sfpplus1-sfp-sfpplus2:10218 |
| CRS326-4C+20G+2Q+ | combo1-combo4:10218; ether1-ether20:10218; qsfpplus1-1-qsfpplus2-4:10218; ether21:2028 |
| CRS326-24S+2Q+ | sfp-sfpplus1-sfp-sfpplus24:10218; qsfpplus1-1-qsfpplus2-4:10218; ether1:2028 |
| CRS354-48G-4S+2Q+, CRS354-48P-4S+2Q+ | sfp-sfpplus1-sfp-sfpplus4:10218; qsfpplus1-1-qsfpplus2-4:10218; ether1-ether48:10218; ether49:2028 |
| CRS504-4XQ-IN | ether1:2028; qsfp28-1-1 - qsfp28-4-4:10218 |
| CRS510-8XS-2XQ-IN | ether1:2028; sfp28-1 - sfp28-8:10218; qsfp28-1-1 - qsfp28-2-4:10218 |
| CRS518-16XS-2XQ | ether1:2028; sfp28-1 - sfp28-16:10218; qsfp28-1-1 - qsfp28-2-4:10218 |
| CSS610-8G-2S+, CSS610-8P-2S+ | ether1-ether8:10218; sfp-sfpplus1-sfp-sfpplus2:10218 |
| D52G-5HacD2HnD (hAP ac²) | ether1-ether5:9124 |
| C52iG-5HaxD2HaxD (hAP ax2) | ether1-ether5:9214 |
| C53UiG+5HPaxD2HPaxD (hAP ax3) | ether1-ether5:9214 |
| L41G-2axD (hAP ax lite) | ether1-ether4:2026 |
| cAP ac | ether1-ether2:9124 |
| GPEN21 | ether1-ether2:10222; sfp1: 10222 |
| wAP60G, LHG60G | ether1:9124 |
| RB260GS series, CSS106-5G-1S, CSS106-1G-4P-1S | ether1-ether5:9198; sfp1:9198 |
| RBFTC11 | ether1:4046; sfp1:4046 |
| RBM33G | ether1-ether3:2026 |
| RBM11G | ether1:2026 |
| RB760iGS | ether1-ether5:2026; sfp1:2026 |
| RB411 series | ether1:1526 |
| RB433 series, RB450, RB493 series | ether1:1526; ether2-ether3:1522 |
| RB450Gx4 | ether1-ether5:9214 |
| RB411GL | ether1:1520 |
| RB433GL, RB435G , RB450G, RB493G | ether1-ether3:1520 |
| RB800 | ether1-ether2:9500; ether3:9116 |
| RB850Gx2 | ether1-ether5:1580 |
| RB921UAGS, RB922UAGS | ether1:4076; sfp1:4076 |
| D23UGS-5HPacD2HnD (NetMetal ac²) | ether1:9214 ; sfp1:9214 |
| RB953GS | ether1-ether2:4074; sfp1:4074; sfp2:4076 |
| RB2011 series | ether1-ether5:4074; ether6-ether10:2028; sfp1:4074 |
| RB3011 series | ether1-ether5:8156; ether6-ether10:8156; sfp1:8158 |
| RB5009 RB5009 series | ether1-ether8: 9796; sfp-sfpplus1: 9796 |
L009 series | ether1: 8158; ether2-ether8: 8154; sfp1: 8154 |
| RB44Ge | ether1-ether4:9116 |
All wireless interfaces in RouterOS (including Nstreme2) support 2290 byte L2MTU.
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Configured in the "/mpls interface" menu, specifies the maximal size of the packet, including MPLS labels, that is allowed to send out by the particular interface (default is 1508).
Make sure that MPLS MTU is smaller or equal to L2MTU. MPLS MTU affects packets depending on what action the MPLS router is performing. It is strongly recommended that MPLS MTU is configured to the same value on all routers forming the MPLS cloud because of the effects MPLS MTU has on MPLS switched packets. This requirement means that all interfaces participating in the MPLS cloud must be configured to the smallest MPLS MTU values among participating interfaces, therefore care must be taken to properly select the hardware to be used.
You can read more about MPLS MTU here.
MPLS Switching
If the packet with labels included is bigger than MPLS MTU, MPLS tries to guess the protocol that is carried inside the MPLS frame:
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