Citrix NetScaler EE, Installation And Configuration Manual

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This is because with this interface down, the IPHOST routes are flushed from ME-DC_Router’s routing table.
b. If this happens, MCN will forward the encapsulated packet destined to one the BR1 VIPs to ME-DC Router and back
from router to the MCN and loop continuously.
On the ME-B R1_Ro uter: On the ME-B R1_Ro uter:
Advertise 172.58.3.x network to ME-DC_Router with a higher cost than the cost advertised for the same network by DC, if
the same AREA-ID is used between
ME-B R1_Ro uter ME-B R1_Ro uter <-> ME-DC _Ro uter ME-DC _Ro uter and ME-DC _Ro uter ME-DC _Ro uter <-> DC (S D-WAN) DC (S D-WAN) .
a. Based on the cost metric computation of OSPF 10^8/BW and the cost for route prefixes are based on the interface
type. SD-WAN appliances advertise the virtual path and virtual WAN specific static routes to the external or peer routers
with default SD-WAN cost of 5.
b. If the ME-BR1_Router is also advertising 172.58.3.0/24 as an internal OSPF type 1 route alongside DC (SD-WAN) which
also advertises the same prefix as interal ospf Type 1 route, then according to cost computation, by default the ME-
BR1_Router’s route will be configured, as the cost is lesser than SD-WAN’s default cost of 5. To avoid this and make SD-
WAN appliance chosen as preferred route initially, the interface cost of (172.58.3.1) needs to be manipulated to make it
higher on the ME-BR1_Router so that DC SD-WAN route is configured in the routing table of the ME-DC_Router.
This also ensures that when the DC SD-WAN appliance fails, the alternate route to use ME-BR1_Router as the next
preferred gateway will ensure uninterrupted traffic flow.
Use ME-DC_Rout er as a source f or advert ising 17 2.58.8.0/24 net work t o bot h DC SD-WAN and t he ME- Use ME-DC_Rout er as a source f or advert ising 17 2.58.8.0/24 net work t o bot h DC SD-WAN and t he ME-
BR1_Rout er BR1_Rout er
With this route, the DC SD-WAN can send packets to the upstream router being aware of the LAN subnet after
decapsulation. If DC SD-WAN goes down, the legacy routing infrastructure would help ME-BR1_Router use the ME-
DC_Router as the next hop to reach the 172.58.8.x network.
To configure OSPF export ed rout es as Type1 under Basic OSPF Set t ings To configure OSPF export ed rout es as Type1 under Basic OSPF Set t ings
1. Configure Virt ual Int erf aces Virt ual Int erf aces and WAN links WAN links on both DC and Branch sites to create Virtual Path between them.
2. Under Connect ions Connect ions->[MCN MCN]>Rout e Learning Rout e Learning->OSPF OSPF ->Basic Set t ings Basic Set t ings, select Export OSPF Rout e T ype Export OSPF Rout e T ype to be
T ype 1 Int ra Area T ype 1 Int ra Area.
3. Save the configuration, stage and activate the same.
4. You should be able to see following two route types under Export OSPF Rout e T ype Export OSPF Rout e T ype
- Type 5 AS External
- Type 1 Intra Area
5.
After activation of the changed config, you can see the Route Type changes under C o nfigura tio n C o nfigura tio n->Virtua l WAN Virtua l WAN->View C o nfigura tio n View C o nfigura tio n-
>Dyna mic Ro uting Dyna mic Ro uting
.
6. Routes should be advertised as Type5 External AS by the SD-WAN appliance. Routes learnt through SD-WAN should
be displayed in the neighboring routers as Type5 AS External routes.
To configure OSPF export ed rout e weight under Basic OSPF Set t ings To configure OSPF export ed rout e weight under Basic OSPF Set t ings