Restore SVP_R_ROUTE_REQ, and all that goes with it.
Interpret sl3a_uport == 0 in SVP_R_VL3_ACK to indicate the VL3 IP is a next-hop router.

@@ -59,12 +59,12 @@
         SVP_R_LOG_REQ           = 0x09,
         SVP_R_LOG_ACK           = 0x0A,
         SVP_R_LOG_RM            = 0x0B,
         SVP_R_LOG_RM_ACK        = 0x0C,
         SVP_R_SHOOTDOWN         = 0x0D,
-        SVP_R_REMOTE_VL3_REQ    = 0x0E,
-        SVP_R_REMOTE_VL3_ACK    = 0x0F
+        SVP_R_ROUTE_REQ         = 0x0E,
+        SVP_R_ROUTE_ACK         = 0x0F
 } svp_op_t;
 
 typedef enum svp_status {
         SVP_S_OK        = 0x00, /* Everything OK */
         SVP_S_FATAL     = 0x01, /* Fatal error, close connection */

@@ -72,11 +72,11 @@
         SVP_S_BADL3TYPE = 0x03, /* Unknown svp_vl3_type_t */
         SVP_S_BADBULK   = 0x04  /* Unknown svp_bulk_type_t */
 } svp_status_t;
 
 /*
- * A client issues the SVP_R_VL2_REQ whenever it needs to perform a VLS->UL3
+ * A client issues the SVP_R_VL2_REQ whenever it needs to perform a VL2->UL3
  * lookup. Requests have the following structure:
  */
 typedef struct svp_vl2_req {
         uint8_t         sl2r_mac[ETHERADDRL];
         uint8_t         sl2r_pad[2];

@@ -122,38 +122,10 @@
         uint16_t        sl3a_uport;
         uint8_t         sl3a_uip[16];
 } svp_vl3_ack_t;
 
 /*
- * A client issues the SVP_R_REMOTE_VL3_REQ for a far-remote (cross-DC) VL3 IP
- * address.  The server may take longer because it may query cross-DC to get
- * the answer for our response.
- */
-typedef struct svp_rvl3_req {
-        uint8_t         srl3r_srcip[16];
-        uint8_t         srl3r_dstip[16];
-        uint32_t        srl3r_type;     /* Same as SVP_R_VL3_REQ */
-        uint32_t        srl3r_vnetid;
-        uint16_t        srl3r_vlan;
-        uint16_t        srl3r_pad;      /* XXX KEBE ASKS, necessary? */
-} svp_rvl3_req_t;
-
-/*
- * The remote-VL3 response contains more than the regular VL3 one, because
- * overlay needs to rewrite the MAC header completely.
- */
-typedef struct svp_rvl3_ack {
-        uint32_t        srl3a_status;
-        uint8_t         srl3a_dstmac[ETHERADDRL]; /* MAC of the target. */
-        uint8_t         srl3a_srcmac[ETHERADDRL]; /* MAC of the target's rtr */
-        uint16_t        srl3a_vlanid;
-        uint16_t        srl3a_uport;
-        uint32_t        srl3a_dcid;     /* Remote Data Center ID. */
-        uint8_t         srl3a_uip[16];
-} svp_rvl3_ack_t;
-
-/*
  * SVP_R_BULK_REQ requests a bulk dump of data. Currently we have two kinds of
  * data tables that we need to dump: VL3->VL2 mappings and VL2->UL3 mappings.
  * The kind that we want is indicated using the svbr_type member.
  */
 typedef enum svp_bulk_type {

@@ -259,10 +231,42 @@
         uint8_t         svsd_mac[ETHERADDRL];
         uint8_t         svsd_pad[2];
         uint32_t        svsd_vnetid;
 } svp_shootdown_t;
 
+/*
+ * A route-request (SVP_R_ROUTE_REQ) queries the local SVP server to get a
+ * far-remote (i.e. another Triton Data Center, nee. SDC) SVP server for
+ * far-remote networks.  Modern overlay modules will request IP destinations
+ * for remote-Triton networks, but they must know how to reach the
+ * remote-Triton SVP server.
+ */
+typedef struct svp_route_req {
+        uint32_t        srr_vnetid;     /* Requester's vnet ID. */
+        uint16_t        srr_vlan;       /* Requester's VLAN ID. */
+        uint16_t        srr_pad;        /* Zero on xmit, ignore on receipt. */
+        uint8_t         srr_srcip[16];  /* VL3 Source IP. */
+        uint8_t         srr_dstip[16];  /* VL3 Destination IP. */
+} svp_route_req_t;
+
+/*
+ * The far-remote Triton Data Center will answer with the requisite information
+ * to send overlay packets to the appropriate far-remote CNs.
+ */
+typedef struct svp_route_ack {
+        uint32_t        sra_status;     /* Status. */
+        uint32_t        sra_dcid;       /* Far-remote Data Center ID. */
+        uint32_t        sra_vnetid;     /* Far-remote vnet ID. */
+        uint16_t        sra_vlan;       /* Far-remote VLAN ID. */
+        uint16_t        sra_port;       /* Destination UL3 port. */
+        uint8_t         sra_ip[16];     /* Destination UL3 address. */
+        uint8_t sra_srcmac[ETHERADDRL]; /* Far-remote VL2 source. */
+        uint8_t sra_dstmac[ETHERADDRL]; /* Far-remote VL2 dest. */
+        uint8_t         sra_src_pfx;    /* Far-remote VL3 source prefix */
+        uint8_t         sra_dst_pfx;    /* Far-remote VL3 dest. prefix */
+} svp_route_ack_t;
+
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* _LIBVARPD_SVP_PROT_H */